why are they fucked? you can just switch to plants grown previously further down the south, you can already now grow figs, lemons, etc. for instance, let alone tomatoes/peppers
No you cannot "just" do things like that sadly... you still need water, as much as 10L/day/sqm during a heat wave. Also you need proper night/day temperature cycles, a reasonable early/late frost timing as to not kill your new plants, the soil has to match what you want to grow, etc. it's a whole dance between many many factors.
Flowers and pollen also get absolutely fucked by high heat, tomatoes stop growing when it's too warm. I know a farm where they lost most of their tomatoes, they cooked on the plant and fell to the ground.
We should just turn some fields into PV plants...