If you are planning on skiing exclusively in the Cottonwood Canyons (includes Snowbird), then staying in the Salt Lake area is quite convenient (obviously not as convenient as staying at the resort itself however). Depending on where in the SL Valley you stay, you can be to Snowbird within 15-45 minutes drive. You might consider a hotel in Cottonwood Heights or Sandy which are close to the canyon entrances. Otherwise, downtown SLC is about a 35-40 minute drive to Snowbird.