Double ditto on swinging through Cody. Several options there. How many are you cooking for?
If you don't want to stock up in Cody then ditch some of extra items you rarely use and stock that storage with canned goods. Canned shredded chicken, tuna, ham etc store compactly.
Tins of stew and soups as well as other canned goods can stow beneath the banquet and soup and sandwiches are always good after a long day of walking and sightseeing. Don't put them in the basement storage with an outside door as bears can easily open those. Freeze dried soups are pretty tasty too. Don't forget instant oatmeal, cream of wheat, instant mashed taters and other instants. Take some fresh fruit: it's worth it.
A trip like yours is all about the sights and experiences: not gourmet meals every night. Go basic with sandwiches, soups and cereals. If you have the freezer space make your favorite casserole and freeze it for a break from the basics.