Can I store all the keys from a multisig account on Ledger devices? Say that I create a 2/3 multisig wallet using Copay. 


Can I store all three keys on different Ledger devices?
Can I store all three keys on the same Ledger device?
I am searching for an answer to the same question. From what I have read so far, the Ledger Nano S does not support multiple BIP44 HD accounts, but I have contacted Ledger for confirmation of this.

This feature would be very useful to distribute the backups of your ledger device (no single backup would be able to steal your funds) but maintain the convenience of being able to sign your own transactions without the need for a 3rd party.

I will update this answer when I receive a response from Ledger.

Update

Still no response from Ledger, but I did find another solution to the problem I was originally trying to solve, so I thought I'd share.

Ian Coleman has developed an implementation of Shamir's Secret Sharing Scheme for BIP39, allowing you to split a single BIP39 mnemonic into a number of parts, which are able to be restored similar to an m-of-n multi-sig wallet - ie You could generate 4 parts to the backup, and allow the full backup to be restored with only 3 of the 4 parts.

More info can be found in the GitHub link: https://github.com/iancoleman/shamir39