@Grey WolfAyup, he's already lining out many issues which will only occur post college. I doubt he'll continue long after college (i.e. past those specific points, yet with the character's future plans, he's got more than enough material to work with. Yet, as he also notes, while the character's themselves entering as a group to pamper their grandkids, that's still a long ways off, and likely well beyond the scope of the series.
Though where he'll draw the line is an open question, as I doubt whether even he knows. Yet, I keep urging him not to dedicate his entire life to the story, but to expand his writing, as each new project tends to advance your overall skills (i.e. each tends to be as limiting as it advances one's skills).
Still, I plan to continue reading it, as long as I'm still able, and yet, despite my age and poor health overall, I seem to be destined to live a long life, despite myself. ;)