Time to structure the plan. Let's peak at 61 miles: that way I will have one week cutback and then just a very slight increase from the week before.

01/16: Week 14, 43 miles.
01/23: Week 13, 46 miles.
01/30: Week 12, 49 miles.
02/06: Week 11, 49 miles.
02/13: Week 10, 52 miles.
02/20: Week 9, 56 miles.
02/27: Week 8, 52 miles.
03/05: Week 7, 57 miles.
03/12: Week 6, 61 miles.
03/19: Week 5, 59 miles.
03/26: Week 4, 52 miles.
04/02: Week 3, 54 miles.
04/09: Week 2, 50 miles.
04/16: Week 1, 46 miles.
04/23: Race week, 37 miles.

Week of 1/16: total of 43 miles including 12 and 9 mile long runs (two!), 8 miles tempo day (1.5 to 2 miles of warmup, 2 x 2 miles at ~6:45, 2-3 minutes jogging to recover between the intervals, and then cooldown). Easy days: 3 x 4.67 miles at around 8:00 min/mile.