Got this idea of Knoxi. Warm water sprayed on to your hands while riding in the winter. Works a treat should have done it years ago. Easy to install. Just place the tube up the pisser hose. $14 dollars or $17 delivered. T fitting is stainless. 3 meters of uv resistant plastic tube. A lot more flow when it is in the water. Picture is with ski on tap water.
Flan you can go full pro.. Run the tube inside your handlebars and drill holes through the grips. Seen that before, super warm.