So I have started to rebase a big branch on my current master (75 commits). I know it will take me a day or so. In the meantime, I need to address some comments on another PR.
How can I suspend my current rebase to amend my PR without re-cloning the repo or copying the folder (these would work of course)? Is this even possible?
There is no built-in way to "pause" a rebase that I know of, although you can certainly accomplish something like it with enough git finesse.
However, in the case you've described, a much simpler solution is simply to do your rebase in one working directory, and do the other changes you need to do in a different working directory.
To get a new working directory, you can either:
Use a simple
git clone to get a new working directory (AND a local repository, so you'll need to push/pull your results pack the original working directory).
Or, take a look at
git worktree, which can help you manage multiple worktrees using the exact same repository data.