Your regular clothes for winter that keeps you warm and give you a freedom of movement will do plus boots and gloves. Wearing a motorized helmet is a must plus elbow and knee pads. Lifejacket is recommended on ice or hard surfaces. Snowfer sailors use the same windsurfing rigs, have the same feeling and same techniques in general. In my experience of winter sailing since 1985, I have never damaged one or seen anyone's sails damaged because of cold temperature.
All new sails stand cold temperature very well.
Ultraviolet rays from the sun does more damaged to the sail than cold temperature. Absolutely not, Snowfer sailors are constantly in motion which keeps body temperature very warm even on those cold, frosty days. If you add up all the start-up cost plus how many hours you are able to sail in a period of twenty years, you will come to an average cost of .28 cents per hour to operate the Snowfer. I think it's quite reasonable if you compare it to other winter sports. If you use the board properly as recommended you can get at least 20 years out of it.