Only two days in Yellowstone!

Hi,

We are fortunate enough that this summer we'll have the opportunity to tag on a two day trip to Yellowstone to a business trip. I know this is not enough time so I want to try and hit what we can in two days without trying to do too much. Here's my plan:

Day 1: fly into Cody, WY very late
Day 2: up early, explore Cody (Buffalo Bill museum, Pioneer Town, Rodeo)
Day 3: up and out of B and B by 9:30. Head to North Entrance of Yellowstone. Spend night in park near the lake.
Day 4: continue exploring Yellowstone and drive south. Need to end in Salt Lake City.

On day 2, should we skip doing some of those things in Cody and head out on the Chief Joseph Scenic Highway and back?

Should we try to go north at all or stick to the Grand Canyon/Old Faithful area? On Day 4, I'd like to do the scenic loop out of Jackson Hole into the Grand Tetons. We can end very late in SLC and know that day 4 will be lots of driving.

We'll also have a week in Salt Lake City and have the nights for adventures. Plan on hearing the Morman Tabernacle Choir sing one of the nights. Any other must sees or good restaurants (without a car unfortunately) in SLC? We'll be staying down town, right near the temple square.

Thanks for any tips in advance!