Actually my advice would be to wait before you pull the trigger. The main reason is snow conditions. Utah, like anywhere else can get skunked. Two years ago they had a horrible season until late March. Feb was crap. Knowing that conditions are decent is better than having to cancel your trip and incur all sorts of fees. One caveat. Plane tickets are not getting cheaper, that would be the only reason I would buy now. Otherwise, it's easy enough to find affordable rentals in SLC.