Do you really only need 6-8 hours training? Well your new school might agree but wwith that level of experience and a prolonged break I suspect they will spend a lot of time revised things you have forgotten - or possibly never knew.
I would go with this, probably at least 2-3 hours just getting you back to where you were so I should allow 10-15 hours to finish, given the weather though it should be no problem doing this in a week if you can do full time in that week - 2-3 hours a day is fine and at least gives good continuity.