Hibernate and suspend are different. I configure my laptop to suspend for 3 hours before hibernating. That means I can close the lid for lunch or a commute and instantly resume, but if I leave my laptop in my bag over a long weekend, the battery isn’t drained. Does it save much battery? Dunno. A few % over a few days maybe.

If it’s a laptop and you want to be able to hibernate, swap must be large enough to hold system memory, plus a little extra just in case. Other than that, everything depends on the workload. Generally, no. Maybe a few gb in most cases.

I run a single headscale node on one of my free Oracle OCI instances, and connect about a dozen devices to it. No fear of adding friends either, since it’s free.