And yet, this too has some hidden risks. Did you know that you need all of your XPUBs (or zpubs or ypubs) if you are going to use the "x" number of keys in an x of y setup? In other words... There are scenarios where you can have 2 of 3 seeds in a 2 of 3 multisig setup and and be shit out of luck. So, you have to safeguard all of your xpubs as well. So you could store all three x pubs with each seed, but then you have also reduced your security somewhat. Because all an attacker needs in that scenario is two seeds, where if the XPUBs are elsewhere then the attacker cannot access anything with just 2. Now a view only electrum wallet or the like can take care of this. Gives you a way to send coins to storage and also a way to backup your 3 XPUBS. That view only wallet could be encrypted and stored electronically in an email, or USB key etc (This is it's own rabbit hole of risks that I will not go down lol).
One thing I played with as an idea once was rather than worrying too much about keys was to generate and sign transactions but not put them on the blockchain. If discovered, these transactions could not be used to steal funds (other than if stolen by the intended target) and are easily invalidated if you suspect foul play by simply spending the coins.
You might also be able to do some stuff with nlocktime.