You might want to reach out to
@DopeyBadger on these forums to see if one of his custom marathon training plans would be a good fit for you. His plans are, at heart, time-based rather than distance-based which can result in more manageable long training run mileages. For example, I train at basically a 4:00 marathon pace and my longest runs top out at 16 miles. At your estimated pace, you'd likely be under 15 miles for a maximum long training run. I'll let him get into more of the specifics if you choose to explore that route, though.