This is just my personal strategy for handling this

I sometimes add a bunch of new anki cards to my decks (activate them), then it works a few days, sth happens that gets me out of that learning routine, I skip a few days and I end up with a backlog of 1000-2000 cards … This actually happens quite often for me :S

And honestly doing 2000 reviews or so in one day is just too much for me, like if its really just 7 days or so its often quite okay, but lets say you go on a trip and it becomes 30d, a ton of cards will be crazy hard to get, its basically relearning half the stack of due cards.

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My strategy

What I do in this case is pretty easy tbh, I just clear the small decks that have below 100 cards right away, as thats usually acceptable. Then for the few remaining big decks I create filtered decks on them wit

deck:Japanese is:due prop:due=0

this creates a deck with only the cards that would be due for today, not the overdue ones, which often makes it quite a small & doable deck i.e. less than 100 cards. After clearing this deck I often go and change the filter to sth like

deck:Japanese is:due prop:due>-1

this lets me clear the cards that were due yesterday, then set it to prop:due>-2 etc. etc. when I’m done for today I just quit. And the next day I continue where I left of just with -1 added to it, since one more day passed. That prevents new cards from piling up and you can slowly clear your backlog without having to do everything at once.

creating a filtered deck