I sat ALL the exams on Monday and Tuesday because I had to travel from abroad and didn't want to have to come back just for a single exam on a Monday.
It is possible and not that stressful if you are prepared.
CATS has always treated me professionally and I expect to pass my ATPL exams with little problems.
As far as where to stay, it has been a while, but I remember staying in a B&B on High Street in Cranfield and there was a bus that went right to the university. Very easy. Short walk to CATS.