I do not know any wallet for making PSBT but you can use some open source wallet with multiple coin support offline and have the master public key on a watch-only wallet.

I know Unstoppable wallet supports that. Maybe you can try it.


Maybe you can have multiple of the wallet offline so you can just select on one for making transaction if there is any need which will then become online wallet.

Some people just use the method to hold their coins and not spend from it at all.