Florida will be underwater by then
Agree. I see us as a Likely D, Virginia-sized state with a whole lot of single-issue-climate-change-policy voters, maybe Louisiana is like this too (just with a much smaller total population), and to a lesser degree NC and VA
I could see a dystopian scenario where the Gulf Coast states are all near unanimous D with half their current EV due to single issue climate change voters, but 2050 is way too soon for that. I could see it in 2100, though.
When it comes to New England, I think there could be a big divergence of trends between CT and MA and the other states. Dem improvement with white college+ voters should be able to completely lock down CT and MA even if working class whites in New England start voting like they do in Appalachia (which is not remotely impossible).
Also, I wouldn't rule out Texas crossing California for 1st place in population by the 2050 census, though it probably won't happen until 2060-2070.