I think "1 hour’s worth" is the correct way to write this. Therefore, in the plural case, I assume the correct choice is "2 hours’ worth". Which one is it?
Just wondering because someone edited a question of mine to remove these apostrophes.
You are correct. There is no logical reason for the number (not case) to be plural with one. It's like saying a worth of one hour, so the genitive (aka possessive) case would be correct.