Shaving my cats

My cats have their winter coats now - I had them groomed during the summer to prevent hairballs. (Boy did they look funny!, but there was MUCH less hairballs)
Now that they have their winter coats, do I need to have them groomed as there seems to be a lot of fur around....but I was wondering, wouldnt they get cold?
Any advice is MUCH appreciated.

If they remain indoors, keeping them shaved is fine. If they go outdoors, I would let it all grow back, because they will need it

Yes, if they are indoors you my shave them in the winter.

If they're indoors, you can ask your groomer to modify the lion clip. I have one client that has me clip her cat long. I use a #3 (1/2") or #4 (3/8") blade, and it "thins" out the coat without making it bald short. Of course, this will only work if your cats are well brushed and matt-free. It's a thought.

Cinnamon got a lion cut back in August (i think it was august). She looked so cute. Her hair has grown in (not long like it used to be though) and she is kind of shaggy looking. I've noticed ever since I got her hair cut though, she lays more underneath the blankets! When it gets warmer again, I will get her groomed again, because I think it really helped with the hairballs.