I can't see now knowing all the facts how a year or two is going to make any difference if he's already a seasoned hunter with you and also gramps. In two years he'll still be in school so I think 3 days off is no big deal if he get decent grades whether it's now or at 16. Just let the guest hunters know ahead of time that he'll be there and that gives them the choice well ahead of time as to whether they show up or not.