If you insulate the house well, you can heat it with a 1500 watt heater. Radiant floors are an expensive solution to a simple problem. Nice, but complicated. Cellulose insulation into a Larsen truss wall will keep you plenty warm, no matter what is happening outside. Windows are nice, but go outside if you want to look at the view- this is also a cheaper alternative. Look into prefabricated houses, just to see what options there are. Don't overthink it. It's a box you don't want to have to maintain for as long as possible: roof should last thirty years, minimum. Windows should not require reglazing- I hate doing this. Paint doesn't last for beans now that it has no lead in it. Etc. Do it once, do it right. Look around the neighborhood and see what others have done that makes sense. Or not.