I think it's time to start a new pseudophilosophy called shorttermism. Basically take whatever longtermism proposes and do the opposite.
If you take a radical view of longtermism to its logical conclusion ie the heat death of the universe and it ultimately doesn’t matter, so you live for the immediate here & now. A sort of radical nihilist paradoxical longtermist hedonist. Seems dangerous. Can justify anything.