When I was at Jackson for the Steep and Deep camp last month I had the same quandary... There's a lot of people that wear boots onto the bus and a lot that carry boots.
I wore boots onto the bus one time and carried the other days. It's a LONG day in ski boots if you boot up in your room. Count on 30, 40 minutes additional on each end of your ski day for transportation between town and the mountain. How comfy are your boots? If you can't wait to get them off that last half-hour to your hotel is going to
suck.
As
@mdf said, there are limited places to get booted up at the mountain. However, there is an (apparently new) tent-like structure in front of the Bridger Center that I would boot up in and dump my boot bag for the day. It's not locked, guarded or anything, but it's warm and comfy.