Power button no good in snow/ice. Winter button starts you off in 3rd gear as you pull out from a stop to help prevent wheel spin. As was already stated, you are always in 4 hi. If however you become stuck in deep snow (or anything else) and need to use 4 lo you need to stop, shift into nuetral and then move the transfer case shifter to 4lo. While in 4lo you will not be able to go faster than about 40 mph. When 4lo is no longer needed you just stop again, shift into nuetral and put it back in 4hi.

Better yet move out here to a Arizona and you won't have to worry about all that white stuff!