There's no obligation for everyone to enter every contest.
Perhaps one solution could be to run more than one contest concurrently. Not necesserially "there's always two going at a time", but perhaps the creation phase for the next contest could start when this one's voting phase begins, or something like that. This allows a more frequent schedule without rushing individual contests, especially since the voting phase doesn't really require much effort from either participants or voters - no further updates are being made (at least not publicly), and no further playing is generally needed.
I do also feel two months is a bit excessive for both phases, really, especially given that late entries are allowed these days. And it could become a problem when people are wanting to enter levels from upcoming packs - I had to think about whether or not to withdraw my level in case LPVI was ready sooner than expected, but the decision to make it 80 levels instead of 50-60 made this no longer an issue.