Another Mainer (by birth at least) checking in on the conversation. Born in Biddeford, raised in the Kennebunks, so we know the Wells station well. Heck, the drive to Logan is only another hour and a half after Wells, and no North to South Station transfer sounds like a better plan.
Be sure you realize that parking at Logan for a 10 day trip will run you big bucks unless you are careful. It may pay to do an airport hotel overnight on the way down, and they'll shuttle you back and forth to Logan, and the hotel cost will be cheaper than parking in Logan Central parking lot ($22 for the first day, $11 a day afterwards, or $121 for a 10 day trip) or the Logan Economy Lot ($16 a day, $96 weekly, possibly $144 for a 10 day trip) or Park-n-Fly ($123 for a 10 day trip). Another option might be driving as far as Peabody Mass (off I95) and pulling in to Logan Express, which will run you $99 for a 10 day trip. Perhaps just a expensive would be a Limo service from your home in Waterville direct to Logan, if you can count on them to be there for your return.
Good luck!