The requirement for groundschool does not specify that all groundschool must be completed in one block, and as Alex has said the requirement is for 65 hours, or 2 weeks total.
If you speak to a number of schools they might allow you to accrue groundschool time on individual days on a mutually convenient basis and to minimum hours. However the schools are not obliged to be so helpful as that so it must be a case of negotiation between you and the school.
Best of luck.