Mid-Coast Maine has always been a road trip, not a destination — you point the motorhome north out of Portland and let the coast pull you the rest of the way to Acadia. This one was ours with a dog in the back seat and a food allergy to navigate at every stop, which meant every lobster shack, every inn, every trail had to earn its place on the itinerary. It did anyway. Here's how we did it, and how you can too