In the Bitcoin App (Chrome) you are also able to create several accounts. So, for your use case you do not have to buy a 2nd Ledger.
Mentioned here:
https://www.ledgerwallet.com/apps/bitcoinMULTI-ACCOUNT
All your BIP 44 Bitcoin accounts are managed within a unique interface, where you can send and receive, on-demand, in real-time.
But I like the idea of using two Nanos as they will be less used, less likely for hardware failure, and two different pins, and set ups, and seeds.
And I will spread the risk if something goes wrong with one of them, losing the seed, etc...