While it's certainly not my «bzzness», but if moving out of Poland is still on the desk, and saving money on food and services is the primary criterion (while still having a decent life quality and assured internet connection) — there is a better choice than Ukraine, Crimea, Bulgaria, etc. It's Belarus. Food prices are about the same as Russia's (and cheaper, than Poland's), and services are way cheaper than just about anywhere else. See the comparison between neighboring countries: https://noi.md/ru/news_id/209137 (will require translation from Russian). Leaving Gdansk, one can save 100-200 $/month for house heating alone. Total services for a 50 sq.m. flat in Minsk is just about 15-25 $/month
An obvious drawback (for any such movings) — at least one of you (since you're with a lady) have to overcome the language barrier. Learning Belorussian may be a bit easy for a native Polish speaker, but learning Russian (which is omnipresent in Belarus and acts as a second official language) is more far-sighted: it's easy to find a good teacher for, you'd have to learn Cyrillic letters anyway, and there are much more Russian media and speakers to choose from. So if either of you would like to do that — start before moving.
Otherwise you're left with relocation within Poland only, which wouldn't bring on much savings. But here a tip anyway: don't rent a flat on a first nor last floor in a multi-store building. It'll be either cold and-or mouldy, or expensive.