The Russian ones that Seed Savers Exchange and Territorial Seed sell as plants (or seeds, but it’s too late for that!) are all great for cold climates, like ‘Stupice’ and others. Info on both sources can be found in this post: https://awaytogarden.com/more-tomato-secrets I think that Territorial is sold out on all/most but Seed Savers still seems to have stock. Or just get a ‘Brandywine’ at the local farm market…can’t really go wrong w/that. M.