Your goals sounds good. Your general idea of building mileage at a more moderate pace before dropping the mileage and increasing paces for a few months prior is sound.
I would tend to think that running through two consecutive marathon plans is a bit counterproductive. You have done up to 75 mpw in the last year, so I assume you would really love to hit that 80-100 mpw plan. You should be able to do so safely and with strength, but I'm thinking you'll need to really focus on getting your mileage up over the next few months. There would be elements during the first one that made little sense for your progress. I am assuming you are sold on the 12 week Hanson plan. I'll quickly mention that I love Pfitzinger's 18 week plans.
If it were me, I would spend fourteen weeks building before the 12 week Hanson plan. Just speaking very generally here...
- You might get up to 60 mpw within the next month. You are almost there right now. Easy paces. Maybe you make sure your long run and one run during the week is a solid effort. You might throw in a tempo if you are really feeling it, but nothing too crazy or often.
- You might get up around 70 mpw after two months and 80 mpw after three months. If you did, you'd have a few weeks at 80 to really acclimate. By the time your plan started, you'd probably be super eager to start hammering some workouts.
I'd not be too concerned with training paces over the next few months. If your goal is sub-3:10, I think you are being reasonable. I feel like if you up your mileage and stay healthy, you will definitely hit it. You might even surprise yourself. My first marathon was done with Pfitzinger's ~80-105 18 week plan. I hit 80, 80, 78, 85 in the four weeks prior to starting the plan. My highest week ever before that cycle was 62 (highest, not average). I handled the workouts pretty well.
I think you'll be good, but going from 35-55 mpw to running 90-100 mpw with multiple workouts within a few months is no joke. Nutrition, rolling, ice, dynamic stretches, compression, respecting recovery days... all of that is going to play a huge roll in how your body responds. Hopefully you will take care of any problems before they happen. Oh... I loved doubling my recovery days when I first started pushing up towards 100 mpw.