JAA rules are such that you need to enrol with an approved groundschool provider AND that your studies encompass a prerequiste number of hours, a number of which need to be in a classroom environment. That's just how it is.
However, whilst Bristol (good school that they are) have a system whereby you spend two weeks for brush up courses, other schools may have more flexible arrnagements. By sitting the exams in smaller modules, you could break up the number of days off but time off work will still need to be taken. This will, however, give you less leeway in the number of sittings since all exams must be passed in six sittings but maybe a higher chance of passing since there is less pressure at each sitting.
Call some schools and disuss your requirements.
Cheers
Whirls