We spent a week in Sebago Cottage as part of a cycling vacation in Maine. It is well-situated for cyclists, as it is only 7 miles from a large supermarket, 6 from a smaller supermarket and a health food store, and comes with a complete kitchen. Owners Ruth and Sam are also most helpful, and offered more than once to pick things up for us or bring us with them on one of their many trips into town, though we did not need to take them up on the offer. Biking in is also safe, as there is a decent shoulder on the first few miles of highway 127. Although the shoulder disappears halfway to Back River Bend, you can turn onto Old Stage Road before that happens, and have a pleasant ride down a quiet road with little traffic that is only half a mile longer.
The main attraction of Back River Bend is the canoeing and kayaking. Novices can find interesting side channels running off Back River nearby to explore, though this should be done at or close to high tide as they become quite shallow at low tide. More experienced boaters can go up Back River on an incoming tide and explore Hockomock Bay, which you enter 3 miles from the dock. It has miles of bays and coves to explore. Very experienced boaters can go south on an outgoing tide into the Kennebec River and reach Fort Popham and Popham Beach, about 7 miles away, and return on the incoming tide.
While there is not extensive biking in this area, Reid State Park is 8 1/2 miles away and has some great trails as well as two large beaches, and Five Islands is even closer and has a lobster pound that will cook you a lobster and provide you the fixings to have a picnic on their dock. Be aware that, like most places in Maine that are off the beaten track, the roads don't have shoulders and can be hilly at times.
We shared Sebago Cottage with another couple, one of us taking the master bedroom on the main floor, the other couple taking the two bedrooms upstairs as their private suite. Although there is a large table next to the kitchen, we had every meal out on the screened porch, which overlooks Back River. It is very quiet and private. It was a great week, and we plan to return.