After the pileup: how to manage reviews when they all come due at once?

I’d reset back at least a couple levels. Pretty much anything that was guru or less before your break is gone from your memory, and many of the master level items are probably gone as well. You could try resetting back to a level where you have/had almost all master level items and try from there. If necessary, you can reset back even further.

If a reset is still not enough, I’d recommend finding a script that’ll let you reorder your reviews either by level or SRS stage. That way, you can tackle the pile slowly. If you go this route, you’ll want to be sure that you’re at least clearing all of your apprentice stage items out every day if possible. If you have extra energy, you can work on some of the higher stage reviews, but many of them will immediately fall back to guru and apprentice, so you’ll want to make clearing those out your priority. If the number of apprentice items is too large, limiting them by level can help reduce them.

I believe that this is currently the most robust and most well-supported reorder script:

While working through the backlog, just do whatever feels like a reasonable number of daily reviews. If you’re consistent with them now, they’ll come back at a steady, consistent rate later instead of coming back in huge clumps of hundreds at once. The reorder script will help you actually take advantage of the SRS intervals again, letting you basically recreate the WK experience until you get back on your feet and can start doing lessons and reviews normally again.