I can't be sure, but my research shows that gnomes celebrate Christmas like we do. Nothing handed down about a gnome Santa, but this might be a well-kept secret. I think there must be a related concept. Maybe the clan elder plays a role and passes out gifts to the children. As for adults, this is a time for gathering friends and neighbors which brings out the beer and special berry juices! Not too bad.
Gifts could be nuts, ripe berries, new wooden toys and swing sets, with flutes and drums for sing-along's as part of the feast. So, let's assume gnomes do celebrate Christmas. Coming fron Scandanavia, I'm sure it is very colorful and festive.
All remains well.