Worth noting, if the local storage size remains the same, one can seamlessly resize a droplet to have more or less RAM. But storage size can not shrink, so to move to a droplet with less storage would mean a backup and restore.
In any case, before any migration, I would take a backup and download it.
I have in the case of DO migrated up and down with RAM, and indeed I think I’ve done the same with Hetzner. The local storage and IP address stay the same, just a few minutes downtime.