I would move to a smaller instance (though I still check their /all on occasion). However, I wouldn't choose Beehaw, as they've defederated from some large instances.
Beehaw is an old instance (two years, so “old” is relative). They have their own thing going on, and didn’t want to change their groove for the influx of redditors.
Performance on lemm.ee is pretty solid, world was my original instance but it's just my backup now. Hopefully whatever vulnerabilities that are being used to DDoS them can be patched soon.
I've been pretty happy on lemm.ee. I had an account on .world but set this up when I had issues connecting, my original was .ml which I switched from for similar reasons. Here's hoping lemm.ee can remain stable going forward, I'm trying to use the same username for consistency but its a pain losing comment history/ account age when hopping instances.