I suppose than if you have a British passeport and going to Poland, part of EU, it shouldn't be a problem but check it on Polish embassy website.
while you are in Auschwitz - I recommend visiting Krakow and Wieliczka (with a beautiful salt mine).

I will check the embassy web site thank you.

Hi! I just found this Entry requirements (it's Beata here - I just created my account on this website).

Entry Requirements - Passport validity
You must hold a valid passport to enter Poland. For stays of up to three months your passport must be valid for the proposed duration of your stay; you do not need any additional period of validity on your passport beyond this. However, it is always sensible to have a short period of extra validity on your passport in case of any unforeseen delays to your departure. You do not have to wait until your old passport expires to apply to renew it. Any time left on your old passport when you apply will be added to your new passport, up to a maximum of nine months. For passport applications in the UK, you should apply to the Identity and Passport Service. For stays of longer than three months, contact the Embassy of the country to which you are travelling. UK passport holders can use their passports to visit Poland up to the date they expire.

I found it on http://www.fco.gov.uk/en/travel-and-living-abroad/travel-advice-by-country/europe/poland

you're much welcome. Hope you enjoy time in my native country. any questions about a country, customs etc- feel free to ask. if you need a car hire I can llet you know about a one I used. :)

Us citizens only need valid passport to travel to Canada. It can be less than 6months valid.