That is a freaking big roof. Good luck.
I just had two roofs done, no thanks to the windstorm in March. Some observations:
1) Ice prevention is now MANDATORY in Maryland. Period. At least that's what we were told. In any case, it's worth doing - not terribly expensive but could save big repair bills.
https://dgs.maryland.gov/Documents/ofp/2015RoofingPolicy.pdf
http://americanhomespecialists.com/roofing-code/
R905.1.2 Ice barriers. In areas where there has been a history of ice forming along the eaves causing a backup of water as designated in Table R301.2(1), an ice barrier shall be installed for asphalt shingles, metal roof shingles, mineral-surfaced roll roofing, slate and slate-type shingles, wood shingles and wood shakes. The ice barrier shall consist of not fewer than two layers of underlayment cemented together, or a self-adhering polymer-modified bitumen sheet shall be used in place of normal underlayment and extend from the lowest edges of all roof surfaces to a point not less than 24 inches (610 mm) inside the exterior wall line of the building. On roofs with slope equal to or greater than 8 units vertical in 12 units horizontal, the ice barrier shall also be applied not less than 36 inches (914 mm) measured along the roof slope from the eave edge of the building.
2) 3-tab shingles with long warranty/lifespan are really not "a thing" anymore. Manufacturers are getting away from them fast, as one-tab (36" without gaps) architectural shingles have a much higher wind resistance rating. We were told they're getting harder to buy. If you're after a 30+ year roof, don't do 3-tab shingles; you'll actually pay MORE for them than one-tab architectural shingles, and they won't last as long or be as damage-resistant.
3) We had Southernwood do our two roofs, both of which were also involved with State Farm insurance for the storm damage. One was a bit complex, a Cape Cod with dormers; the other was a stock colonial with no weird angles. The prices were reasonable - about 7K per roof, for removal and replacement (not shingle-over-old-shingles), of which we paid only the deductible. I'm not completely sure why, but we had a horrible time with them getting things done in a timely fashion. The rep had some extended family health problems, and basically dropped us entirely while he sorted it out. I think a better company would have handed the job off to a different rep to avoid delay. As it was, it took until mid August to finally get to the job bid in early April - in the meantime, leaving plywood and tarp on the damaged roof.... Ugh. They also failed to replace the step flashing around a chimney - which was explicitly discussed due to existing leakage in that area (but they did come out and redo it quickly once notified of the problem). On a separate new-build job, they also messed up our gutter work, only adding one 4" downspout for an entire 800 sq ft area (which instantly overflowed in heavy rain) and foolishly routing another downspout onto the new section thus adding to the problem. As with the shingles the gutter fix took darn near forever (several months) to get someone out to do it. But we've had good success with them twice before, which is why we worked with them this time. So I'm not sure what has changed.