As the description states, a brand new portable heater would be nice. Of course it would plug into the already existing generator. Since this could be too overpowered, it could use a substantial amount of the generators fuel. They could be found in hunting areas like the inner towns in Sakhal.
Another thing is the stacking of Shemaghs onto a ski mask or wearing one Shemagh on your head and on your face would be nice, allowing for just that bit extra cold protection. I don't think In real life many people would choose over the Shemagh or Ski they would just wear both if it was really that cold.
One last idea, is the ability to actually turn on the geo thermal plant. Create a solid interior, it could be so that inside there is a massive generator needing 3-4 glowplugs in order to run. Two levers need to be pulled with two keys inserted to actually turn on. This will provide power to most of the island. You could combine the first idea where some houses have sockets to run heaters and my beloved Fridge that has been trapped behind the files for many years (I yearn for the fridge).
Anyways, that just my silly 3am ideas. Loving the Sakhal experience so far, even with its ups and downs.