I've faced this same PR problem. Something is very wrong with a software development process when one developer can halt forward progress on the repo by simply ignoring PRs. One solution I've thought about is to automatically accept any PR that sits idle for 48 hours without comments or modification. After that, the reviewers lose the right to complain. If some nasty bug is later discovered, that's what git bisect is for.

An innovative approach. And by submitting a PR on Friday afternoon, you might get a free hand to do anything you like!