That would require a good standard of Polish language skills
Depends, a friend working at the time (no more) in a private institution of 'higher' education showed me something written by a student from.... (let's just say an Eastern Slavic country and leave it at that). The spelling and grammar and style were waaaaay off it was understandable but I'm not sure if the person could pass B2.
This institution would accept all kinds of international students and give them no language support whatsoever... so if a person sticks it out and ends up with a diploma it might not count for the exam (if I had any say it wouldn't).
I'll also mention a couple of students I've had who had spent a number of years in Ireland.
One is extremely fluent (attended more school in Ireland than in Poland) but that type of knowledge is not always.... appreciated by teachers in Poland. Interestingly this person has no special attraction/tie to Ireland and while they often feel out of place in Poland they don't necessarily want to go back to Ireland (international alienation).
Another attended several years of high school in Ireland (graduated there in fact) but struggled to even pass English exams in Poland. Make of that what you will... do high school students have to write at all? What kind of standards are accepted from non-native speakers?
Rounding back to the topic at hand, English speaking countries have extremely... flexible standards as to what they accept from foreigners. Poland doesn't have that tradition (maybe it did before WWII but it doesn't now). So doing anything beyond hitting the books and passing the official test won't necessarily work...
simply no 'easy' way to learn Polish
Anyhoo I'll always recommend this channel for those preparing for exams
Most of her students are also from the East but she has crystal clear diction and her videos are a good way to get that meta-linguistic awareness of Polish that's necessary for higher functioning.