You'll be fine on Michelin MS2s. I live in Utah and have done several 'easy' Moab area trails with them on (Gemini Bridges, Shafer), as well as a couple fairly deep sand routes in the Escalante region, no problems at all.
I used to only run AT tires on my trucks (usually BFG AT), since we like to get off the 'beaten path' every so often. Decided to go with the MS2 last time I needed tires. I didn't notice any decrease in snow or off-road traction. Just less noise and a bit better mpg.
Sounds like a fun trip!