Hi Jordan,
Skipp the acceleration run and do a short foundation run instead, plus a few strides. Don’t worry about the discrepancy in distance between the half marathon and the long run you’re replacing it with. Races and workouts are apples and oranges. Though you certainly should warm up for the race, and if you do you’ll end up close to 14.3 miles anyway. Take Sunday off, do some light activity on Monday (walking, hiking, easy cycling), and resume the schedule Tuesday.