12" all the way up on any windward side. It is like a pizza oven in the winter and stays hot.Congrats.
I have been to Rochester a few times for engg conferences, and demos at RIT. I know it gets cold there.
You said your ICF house uses 12" Reward blocks. Is it ICF all the way up? My house uses 8" ICF, 30-feet in total height, including 14' retaining wall in the rear. Built in the 90s. Fantastic energy performance.