There's several threads discussing issues with Tesla doors/windows and ice and snow buildup and how to deal with it. All cars will have issues with enough ice on them, and moving parts the most. If you know you will be in conditions where there will be significant moisture and below freezing temps, it's a good idea to disable the folding mirrors, and preheat the car before getting ready to go. For me the biggest issue is with the front doors, the windows can freeze which prevents the 1/4 inch drop necessary for functioning, however I found an easy fix: you can slip a card along the glass and down the seal to brake the ice and then it should work fine.
For the FWD, preheating usually is enough, but check to be sure there's no ice on the sensors.