Whether you use one or more wallets to store your bitcoins will depend on the individual, and each method has its own pros and cons. The risk of using only one wallet is that if that wallet gets hacked, we can lose all our bitcoins but this won't happen if we use 2 wallets to store bitcoin. But in return, using 2 or more cold wallets to store bitcoins means you need to protect more seed phrases instead of just 1 phrase compared to using only 1 wallet. This is also a form of pressure because we all know that protecting seed phrases is not easy.

It can be seen that any storage method has its pros and cons, the choice of which method will depend on, there is no specific answer.
For me, if we only have 1 or 2 bitcoins or less, we don't need to complicate things, I think just 1 wallet is enough.