Is Boris Johnson quite popular in Poland?
No. A large percentage of Polish people like to think of the UK as a kind of bugout location, a way to start anew if things go south in Poland (and they don't know or care what UK subjects think of that).
A guy who won a crushing election with the promise of getting Brexit done won't be popular. There's still Ireland but that's not nearly as appealing (too... Irish). There's also a bunch of other countries in western europe but the widespread presence of English in the education system makes the UK the first choice for most (a popular language can also be a burden).