Summary and Reflections
While non-traditional, I highly recommend a northbound flip flop of the Long Trail.
Ending around/on Mansfield provided spectacularly beautiful sights, not to mention it's much easier to travel from Burlington than the "Northeast Kingdom" as its colloquially named.
Starting in the south provides for a gradual work up of terrain and miles and the trail is much more forgiving and well maintained. It's approximately 185 miles to Burlington/Camel's Hump area from the southern border of the Long Trail, which provides a solid ramp up of both mileage and time to get some trail legs under you, not to mention Burlington just happens to be one of the cities most of the private shuttles, public transportation, and trail angels will be amenable to transporting you to/from.
There's a cabin on the short approach trail at the northern terminus you can stay in if required, and the thirty or so miles from the border south to Eden Crossing are pretty rugged/poorly maintained (read: incredibly frustrating) - not the way I'd like to end a long hike.
Regarding timelines, I finished the Long Trail in twenty days, including one zero day and a nero or two. I slack packed two days to help with mileage, and hit the ground running for the first hundred or so miles on the southern end of the trail mainly because I'm stubborn and being surrounded by AT thru hikers got me all nostalgic.
13-17 mile days your first week on the trail may or may not be realistic for you, depending on your experience and fitness levels. I am not a badass all knowing trail god (IANABAKTG), but I did see people of all types and experience levels on the Long Trail.
A large part of long distance hiking is being mature enough (experienced enough over time) to realize what works for you, what doesn't work for you, and making changes appropriately. What works for one person may or may not work for another - and while a lot of long distance hiking experience translates well to other long distance hikes, every environment is unique.
And as always, journal, and take pictures of the people you meet. Overlooks and great but views start to look the same after awhile (especially when looking back), but I find it's the people you'll want to remember the most.