Sometimes, it’s enough in a rehearsal to not go backwards.
In times of great busyness, I do my very best to maintain regularly scheduled rehearsals. Sometimes, of course, it’s impossible – dress rehearsals, exams, performances, etc. can encroach on rehearsal. But if possible, even if everyone is exhausted, I hold rehearsal.
I also don’t hold the same hope for moving forward as I do in a “normal” rehearsal week. I simply hold tight to the intention to not go backwards.
Sometimes, that’s enough.