That’s hilarious about the cat and the shrink film—mine tried to climb it like a scratch post. I totally get what you’re saying about “good enough” with old windows. Have you ever messed with weatherstripping tape? It’s not pretty either, but it’s cheap and peels off easier than silicone. I always wonder if it actually helps much or if I just want to feel like I’m doing something.
Weatherstripping tape is one of those things that looks kind of flimsy but actually does more than you'd think, at least for drafts. I’ve used it on a couple of 1950s wood windows that never quite shut tight. It won’t stop major leaks or condensation, but it definitely cuts down on cold air sneaking in around the edges. The nice part is you can pull it off in spring without a mess—unlike silicone, which I’ve regretted more than once. For the price, it’s not a miracle, but it’s worth it if you just want to take the edge off.