A quick look at this just now suggests it's a tiny bit more complex than I'd hoped. I guess one would have to parse the date and time (maybe ical can do that), but also the HTML needs various text stitching to be legible as line breaks are inserted at random and a large number of punctuation marks are escaped. There are also calls to various XML namespaces that probably provide formatting information that doesn't show up when the unescaped HTML is rendered in a browser. Might make more sense to use the text description provided in the DESCRIPTION: EXTERNAL EMAIL field.
I'm sure there are command-line solutions out there, but I can't find them through a google search.
For the record, here is an example VCS with some identifying info removed. And thanks again!
BEGIN:VCALENDAR
PRODID:-//Microsoft Corporation//Outlook 16.0 MIMEDIR//EN
VERSION:2.0
METHOD:REQUEST
X-MS-OLK-FORCEINSPECTOROPEN:TRUE
BEGIN:VTIMEZONE
TZID:Eastern Standard Time
BEGIN:STANDARD
DTSTART:16011104T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=11
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:16010311T020000
RRULE:FREQ=YEARLY;BYDAY=2SU;BYMONTH=3
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
ATTENDEE;CN=Matthew Price;RSVP=TRUE:mailto:
matt....@utoronto.caCLASS:PUBLIC
CREATED:20210606T203818Z
DESCRIPTION:EXTERNAL EMAIL:\n\nSender is inviting you to a scheduled
Zoom meeting.\n\n\n\nJoin Zoom Meeting\n\nhttps://
us02web.zoom.us/j/111111111 ?pwd=hashhere<
https://us02web.zoom.us/j/11111111 ?pwd=hashhere
\n\npasscode: pass here\n\nOne tap mobile\n\n
+15873281099\,\,82693526704#
\,\,\,\,*320691# Canada\n\n
+16473744685\,\,82693526704#\,\,\,\,*320691# Ca
nada\n\n\n\nDial by your location\n\n
+1 587 328 1099 Canada\n\n
+1 647 374 4685 Canada\n\n
+1 647 558 0588 Canada\n\n +
1 778 907 2071 Canada\n\n
+1 204 272 7920 Canada\n\n +1 438
809 7799 Canada\n\nMeeting ID: 826 9352 6704\n\npasscode: pass here\n\nFind y
our local number:
https://us02web.zoom.us/u/kHIG8dR0U <
https://us02web.zoo m.us/u/kHIG8dR0U>\n\n\n\n\n\n
DTEND;TZID=Eastern Standard Time:20210611T164500
DTSTAMP:20210606T203818Z
DTSTART;TZID=Eastern Standard Time:20210611T154500
LAST-MODIFIED:20210606T203818Z
LOCATION:
https://us02web.zoom.us/j/111111111?pwd=hashhere eW5iQT09
ORGANIZER;CN=sen...@sender.com:mailto:rplosker@inspirations
olutions.comPRIORITY:5
SEQUENCE:0
SUMMARY;LANGUAGE=en-ca:Sender's Zoom Meeting
TRANSP:OPAQUE
UID:long hash w a line break
X-ALT-DESC;FMTTYPE=text/html:<html xmlns:v="urn:schemas-microsoft-com:vml"
xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-mic
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/xml><![endif]--></head><body lang=EN-CA link="#0563C1" vlink="#954F72" st
yle='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal>R<a
name="WinZmBookmark_z1AF06">hea Plosker is inviting you to a scheduled Zoo
m meeting.<o:p></o:p></a></p><p class=MsoNormal><span style='mso-bookmark:
WinZmBookmark_z1AF06'><o:p> \;</o:p></span></p><p class=MsoNormal><spa
n style='mso-bookmark:WinZmBookmark_z1AF06'>Join Zoom Meeting<o:p></o:p></
span></p><p class=MsoNormal><span style='mso-bookmark:WinZmBookmark_z1AF06
'></span><a href="
https://us02web.zoom.us/j/11111111126704?pwd=hashhere"><span style='mso-bookmark:WinZmBookmark_z1AF06'>https:
//
us02web.zoom.us/j/11111111126704?pwd=hashhere</span
><span style='mso-bookmark:WinZmBookmark_z1AF06'></span></a><span style='m
so-bookmark:WinZmBookmark_z1AF06'><o:p></o:p></span></p><p class=MsoNormal
><span style='mso-bookmark:WinZmBookmark_z1AF06'><o:p> \;</o:p></span>
</p><p class=MsoNormal><span style='mso-bookmark:WinZmBookmark_z1AF06'>Mee
ting ID: 826 9352 6704<o:p></o:p></span></p><p class=MsoNormal><span style
='mso-bookmark:WinZmBookmark_z1AF06'>passcode: pass here<o:p></o:p></span></p
><p class=MsoNormal><span style='mso-bookmark:WinZmBookmark_z1AF06'>One ta
p mobile<o:p></o:p></span></p><p class=MsoNormal><span style='mso-bookmark
:WinZmBookmark_z1AF06'>
+15873281099\,\,82693526704#\,\,\,\,*320691# Canada
<o:p></o:p></span></p><p class=MsoNormal><span style='mso-bookmark:WinZmBo
okmark_z1AF06'>
+16473744685\,\,82693526704#\,\,\,\,*320691# Canada<o:p></o
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1AF06'><o:p> \;</o:p></span></p><p class=MsoNormal><span style='mso-bo
okmark:WinZmBookmark_z1AF06'>Dial by your location<o:p></o:p></span></p><p
class=MsoNormal><span style='mso-bookmark:WinZmBookmark_z1AF06'> \;&n
bsp\; \; \; \; \; \;
+1 587 328 1099 Canada<o:p></o:p>
</span></p><p class=MsoNormal><span style='mso-bookmark:WinZmBookmark_z1AF
06'> \; \; \; \; \; \; \;
+1 647 374 4685 Cana
da<o:p></o:p></span></p><p class=MsoNormal><span style='mso-bookmark:WinZm
Bookmark_z1AF06'> \; \; \; \; \; \; \; +1 647
558 0588 Canada<o:p></o:p></span></p><p class=MsoNormal><span style='mso-b
ookmark:WinZmBookmark_z1AF06'> \; \; \; \; \; \;&n
bsp\;
+1 778 907 2071 Canada<o:p></o:p></span></p><p class=MsoNormal><span
style='mso-bookmark:WinZmBookmark_z1AF06'> \; \; \; \;&nb
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+1 204 272 7920 Canada<o:p></o:p></span></p><p class=Ms
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p\; \; \; \; \;
+1 438 809 7799 Canada<o:p></o:p></span></
p><p class=MsoNormal><span style='mso-bookmark:WinZmBookmark_z1AF06'>Meeti
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mso-bookmark:WinZmBookmark_z1AF06'>Passcode: 320691<o:p></o:p></span></p><
p class=MsoNormal><span style='mso-bookmark:WinZmBookmark_z1AF06'>Find you
r local number: </span><a href="
https://us02web.zoom.us/u/kHIG8dR0U"><span
style='mso-bookmark:WinZmBookmark_z1AF06'>
https://us02web.zoom.us/u/kHIG8 dR0U</span><span style='mso-bookmark:WinZmBookmark_z1AF06'></span></a><spa
n style='mso-bookmark:WinZmBookmark_z1AF06'></span><a name=WinZmBookmarkEn
d></a><o:p></o:p></p><p class=MsoNormal><o:p> \;</o:p></p><p class=Mso
Normal><o:p> \;</o:p></p></div></body></html>
X-MICROSOFT-CDO-BUSYSTATUS:TENTATIVE
X-MICROSOFT-CDO-IMPORTANCE:1
X-MICROSOFT-CDO-INTENDEDSTATUS:BUSY
X-MICROSOFT-DISALLOW-COUNTER:FALSE
X-MS-OLK-AUTOSTARTCHECK:FALSE
X-MS-OLK-CONFTYPE:0
X-MS-OLK-SENDER;CN=sen...@sender.com:m
ailto:sen...@sender.comBEGIN:VALARM
TRIGGER:-PT15M
ACTION:DISPLAY
DESCRIPTION:Reminder
END:VALARM
END:VEVENT
END:VCALENDAR