I wouldn’t turn on vacation mode, but I would stop doing lessons until after December. Do your reviews as much as you can, and the App and Guru items will drop, you’ll have burnt more items, and you get to experience the full load of WK in different speeds.
At level 19 (~2600 active items across Apprentice-Enlightened) I went Nope, stopped doing lessons for a while, tried to clear the review queue as much as I could once a day even if I left some undone, etc. I managed to level up to 20 somehow (~2114 active items), but then my Nope got even stronger, stopped doing lessons for ~2 months, and waited until the load was light enough for me to even think of reintroducing lessons (~1100 active items) – and for a while there I did 3 lessons a day. I’ve recently started doing 4 a day now that I’m under 800 active items.
tl;dr: stop doing lessons until you feel like you want to learn more. Don’t stop doing reviews, even if you don’t clear out your review queue every day (10 a day is more than enough if you don’t do any new lessons).