Setting a low max review limit isn’t generally a good idea (because it hides your actual workload of due Review cards from you), but it seems like it could be a good fit for this situation. Set it low for while you’re gone (make sure your Review sort order is set to something helpful), and know that you’ll need to deal with the rest of the backlog when you get back (like with a Catch-up deck).
To prepare in advance, you can’t use “Advance cards” (FSRS Helper add-on) on a single deck, but you can apply a similar idea in your own Filtered Deck to pull some of those cards forward in the next couple weeks. This should help thin out the backlog waiting for you in the future.
High-Stability/long-interval cards will be affected the least by studying them early. Use a search filter like prop:due>=14 prop:due<=28 – not due in the next 14d (because you’re already studying those cards), but due in the 2 weeks after that – combined with prop:s>200 or prop:ivl>200 (either could work) – S greater than 200d, interval longer than 200d. Run the search in Browse and see how many cards you get, so you can fine tune it with numbers relevant for your own collection, and it will give you a suitable portion of your due cards), then Edit > Create Filtered Deck.
For the next 2 weeks, after you study your currently due cards each day, you can rebuild that Filtered Deck to study a quantity of future-due cards. Because the time-span is a fixed 2 weeks, it will advance day-by-day to cover the entire month you’re away.