If I have two PRs, one large and small, against the same branch, is there a merge-order that creates less pain, or is the order irrelevant?

It depends on what you did in the PRs. If the changes are completely independent, then it shouldn't matter. If there are interdependencies (e.g. CI in one PR won't pass unless the other is merged), then you must consider that. Size shouldn't be the deciding factor here.

One is a template merge, the other is a pipeline refactor

You will probably suffer regardless of the order then. Intuitively I would start with the template, since any changes must comply with the new version anyway.

I am also expecting to suffer. I will give it a shot with template first, thanks.

you will most like have a conflict merge to solve after you merge the first one, in which ever order you choose

I am happy to let you solve my merge conflicts, if that is something that brings you joy 😄

come to #C06KSS9L8M7 later, and we can play along

The template conflict was the easy part, but then satisfying all linters is the challenging part. Maintaining a pipeline is essentially a rogue-like

That's probably why I maintain so many

I am missing the part where I receive items that make things easier though

you just gain skills

I wish..