First of all, thank you for your service!
If it was me, I would beef up the wiring(12 Gage min.) and install/replace a few new (good 20 amp) outlets for running back up space heaters, electric fry pans, micro wave and DW's hair dryer. When needed. Free standing oil filled heaters are safe and cheap to use.
Check out the gas heater and make sure it is in perfect condition. A bad gas furnace will let you down when you need it most and can kill you in the bargain.
Don't take chances. Make sure you have plenty of ventilation, especially when cooking with a gas stove. You also need to control the humidity, venting will help.
Best of luck and keep in touch.