There's not an automated way to do that, but you can export all your settings -- your name, PFP, subscriptions, etc. -- to a file on your computer via your profile settings, make an account on another instance, and import those settings. You would need export ahead of time.

For resiliency: if this instance goes down, it does not delete the federated activities from other instances. So other instances that federate with us like fosscad.io will retain all of our posts unless they elect to remove them for whatever reason. Images are liable to be lost unless an administrator specifically configures the picture hosting submodule in a way that caches our images.