Thanks for you query into homes in Maine, and in particular, Falmouth.
There are a number of homes currently for sale with a minimum of 5 acres, and priced below $1,000,000 in Falmouth. Unfotunately, this forum does not allow me to send a link to the listing information for these homes.
I also know a few Brits who live in the Greater Portland area, and I am sure they would be happy to talk with you.
If you would like the listing information sent to you, have any additional questions, or would like more information, feel free to email me at Jennifer.DeSena@NEMoves.com.
Thanks again, and good luck!