I'm really hoping that the HK parts work well. Being able to go with just a single lipo cell really expands the possibilities for small RC.
Maybe the obsolete NIMH packs can be used to heat thin gloves that have nichrome wire threaded through the back side of the fingers...? I've been threatening to try this idea for several years now. Otherwise, I use a 5 gallon propane Mr Heater for some relief, but it's mostly only good for preventing frost bite between rounds.