Canada

Citrus is viable in loads of places in greenhouses if we build the proper infrastructure. Greenhouses with heated soil from geothermal is widely possible throughout the country. Added to greenhouses constructed to take advantage of solar energy as well. The technology exists it just is cost prohibitive at this time. That doesn't matter if you're rebuilding an economy to be self sustainable. You are going to incur lots of debt in the process. We built custom greenhouses for years where we live and are almost completely self sufficient in vegetables, eggs and meat protien for our family as well as my father and sister's families.

Put those in the appropriate sunny places and you can grow whatever you like with very little energy input.

If you add in removing foreign ownership from farmland and rebuilding the soils in growing zones as well as designating areas specifically designated for the appropriate crops you suddenly have the start of a sustainable system. Lots of work. Lots of upheaval. But in the long term a desired outcome from the chaos.