This is also why I've become a bit more skeptical about Nuclear. Renewables + batteries are pretty mediocre right now but if I'm to bet on something for the next twenty years, it's that.
I think nuclear is still really important and has a lot of room for improvement. It's hard to beat its output stability and energy density while emitting no carbon.
Small modular reactors are probably our best bet here. Centrally manufactured, fail-safe designs, short on-site construction times and time-to-first-power-output. It all depends at this point on if the regulatory environment can be improved soon enough for it to matter.
Nuclear is ok for district heating because there aren't many alternatives. Burning gas 20% of the time as backup is not as big of a problem as many people make it out to be. The atmosphere doesn't care when you pollute, just how much, so intermittency is one of the biggest red herrings of all time.
If we had grids with 80% renewables you can start thinking about grid storage but right now it doesn't matter that much.
Just have to figure out how to keep it safe.