I learned today that Piefed potentially makes community migrations easier, particularly in regards to transferring existing posts as well. The mod of the [email protected] community may be taking that route, so you may be able to contact them to see how it goes.

If you’d rather stick to a lemmy based instance, Sopuli.xyz is (in my opinion) quite an excellent medium sized general purpose instance that’s been around a while, and seems to have solid active admins that update to the latest lemmy version quickly. Its server is based in Finland.

Lemmy.zip is similarly sized to Sopuli, and is also a general purpose instance, though with a focus on PC gaming and tech. Not sure where they’re based.

If you’d prefer a smaller instance, Lemmy.cafe has a solid admin (though it’s only run by him, so maybe not as resilient to the bus factor). I think the server is based in the UK. I migrated two of my communities there many months ago, and it seemed to work out well.