I never mind the firewood cutting. I've done it with dad since I was young. He's 66 now and still enjoys it as well as snow shoveling. Keeps him in shape , but not for everyone. I agree with DAND on the SIPS. Ive been a dealer for several years and have built several SIP homes. Its the way to go as far as I'm concerned. You will cut your heating bill in Half or nearly so without any trouble. You mentioned the Geothermal. I've done that as well. We did a geothermal with infloor heating and chilled water forced air cooling. very nice! You will need deep pockets though. That system was close to 50k