:-) No we don't have basements here. Usually if I place them under the patio, shadhouse or in the hothouse then they are fine but about 1/3 - 1/2 in the garden also survive with no treatment cos we don''t really get frost.
No idea. I guess if we want more room we build a second storey?
The plants I'm overwintering are just a few superhots and ones I don't have much or no seed of. white 7 Pot, Naga Viper (not that Im into this hype), Choc Bhut, Douglah, Brain strain and a few ornamentals that I have had for a few years now.