It's not so bad, it's saved on all the signers involved in the multisig, and personally I keep it backed up in various places, as well as encrypted and then in cloud storage.

Technically you just need the 3 xpubs. The config file would just be the xpubs used to build the 2 of 3

You can make a million copies of that though, it would only leak privacy not security. You could also check out a collaborative solution like Unchained because then they would store a backup for you as well.

I do think that multisig works better when it is distributed geographically and between at least two entities. Running 3/5 multisig by yourself in your house is overkill which creates unnecessary complexity IMO.