femalewannabe,
I am doing my ATPL Theory - distance learning - with Bristol Ground School.
The course is split in to two blocks and require 2 x sessions of 2 weeks. In each session 1 week is cramming and the other week is exams.
The total required time for the crammer and exam sessions would therfore be 4 weeks - which should meet your limitations.
At least this was the case a few weeks ago when i last checked. Hope it helps.