I really worry about a bunch of people going over to codeberg. Site's already super slow, but apparently it's quite nice when self-hosted

Anyone who is able to just plop a forgejo instance on their own machines... please do that if possible!

Can a small project do this and (cheaply) be robust to getting slashdotted?

Which is often the dream for a small project.

Probably yes, Codeberg are very transparent about their infra details and they don't seem wild:

https://codeberg.org/Codeberg-Infrastructure/meta