Hello,
If you want to hodl, what's the best strategy for doing so? A single wallet or several? What are the advantages and disadvantages of both options? Maybe it's stressful to use a wallet with lots of satoshis? (whereas several with fewer satoshis is less stressful, isn't it?)
A single wallet or several?
For security reason, it would best to have several wallet holding your fund. This way, if one wallet is compromise, your whole fund won't get stolen. Make sure that each wallet is stored or create in different devices the same reason that when one device gets hacked, you still have your other funds on another devices. It does not make sense if you store your fund on different wallet but is kept on a single device because when the device gets hacked by a malware, all your funds will be at risk.
What are the advantages and disadvantages of both options?
I think the only advantage of keeping your funds in one wallet is easier access, but it would be devastating if the wallet gets hacked. On the other side, having your funds on different wallets created on various devices is somehow troublesome and needs more effort but the security of preventing a total loss when hacked happens is much higher.