Hey Shane, I went through an extremely similar experience with my mid 2010s 58cm Hillborne. My goal was for a nice upright commuter, but I was feeling cramped. There was a lot of seatpost showing that was the first giveaway about it being small. Here's how it looked before I started messing around with things – I also have a 91 PBH and the saddle is at 80 cm here.
This is a 90cm Stem with Albatross bars. I tried going to a 12cm stem and it helped, but it was still a little tight. Trying drops, I had to get the stem way up high to be comfy. That meant a ton of seatpost and a ton of stem sticking out.
I eventually sold it and got a bigger frame to ride more upright with. It was the better solution for me, but your planned bar change should help you stretch out a little.
Good luck trying the Albatross bars, they are fun!
Jeff
