You didn't specify whether you run a dry suit or not. I'd say that if your primary spot is Folly (which is beautiful just visited Force kite and sullivans island) then you problably dont need a dry suit in that area.
With that said. being wet and cold and being completely dry and not cold is very very different.
I really dont like drysuits so I live by the 100 rule on water. Air and water temp must equal 100 degrees or no go.
When it comes to snow if well layered I'm usually sweating my ass off the entire time. I tend to not go if its 10 below or less. We used to go even in -30 and frost bite can be serious for exposed skin not much fun. Typical days are 0-25 degrees on snow.
You've snowboarded your whole life. The problem with downhill is the aweful ride up the hill, depending on hispeed lifts or low speed stop and freeze to death small hills, will determine your comfort level on a resort hill. then you warm up for 5 minutes bombing down the hill and then repeat the process over and over freeze thaw. Just thinking about I'm getting a chill. (we have world class skiing here and haven't participated once since kiting took over my life.
With snowkiting. Just getting out of the car is a workout if you ride deep pow. By the time you are ready to ride your sweating and well prepared for the next step. Riding until you cant take it anymore all the while sweating your ass off. you can easily go up the hill faster then down the hill with a kite.
The coldest part is getting the car warmed back up and feeling the lesser warm air on your now soaked clothes (maybe pack at least some new upper clothes to stave off the wet cold ride back home.)
I really wouldn't worry about the cold its a non issue for snowkiting. unless you get stranded, car wont start, or dont have a warm place to go back too. A good soak in a hotub or hot spring and or a nice warm shower fixes everything.
The only thing that sucks is you can't foil on snow but terrain can make up for the loss of foiling.