Christmas Tree and Brunch?
Here's a list of Massachusetts christmas tree farms, by county.
I would personally not recommend brunch at the Colonial Inn. I've eaten there myself, a number of times over the past ten years or so, and have found that it's gone downhill from what was never really notable to begin with. The atmosphere is definitely cozy, rustic, etc., but the food is pretty mediocre.
swank, concord area must have lots of xmas tree farms; and the Colonial Inn in Concord Center was well liked by some British CH visitors who posted in 2012 iirc. The Wayside Inn has a fan base and there must be many xmas tree farms in sudbury/wayland. mahoneys is there, also russell's
a number of CHs have posted that they like the charming Wenham Tea House for brunch; maybe do a google for a nearby tree farm in hamilton, or Corliss Bros Nursery in Ipswich.