Both the SKP and the KMZ are limited to 10MB on upload to the 3DWH. A
file that's smaller than 10MB may still fail a complexity check to get
into Google Earth, however (particularly as regards complex
geometry). If it's not geometry, but texture images, you might
consider reducing the resolution on some of the images to save space.
In any event you can always try uploading it as a KMZ, and see what
happens to it from there. It'll let you know if it's too complex for
us to use.
-- Allison