I think it depends on where you are staying and your mode of transportation - that's what I take into consideration doing breaks. Sometimes we do them, sometimes not. If you're staying in a resort near AK, it's really not that far to go back to the hotel to take a combat nap, or a swim, even by bus. For me taking a break is more about removing myself from the crowds than say, a nap or a swim - I don't know if that's the case for you husband. There are some places to sit and relax for a break in AK -- some of my favorites are snack stand near safari, the drink stand near Asia that has seating along the water, Starbucks out front. As previous posters have said, if you have the option of changing your dinner reservation, that would help too.
I wouldn't go out of my way to see UP! either. (if you are looking to cut something.) It's cute, I guess, but it's geared toward children doing that Wilderness Explorer challenge. This show seemed less about the birds than the previous version.