We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
Serious gardeners in New England, especially food-gardeners, build coldframes to extend the growing season. Properly done, you can add at least a month to the growing season for some things.
I used to mess with things like that, but I don't bother anymore. If I lived in Maine, though, I'd definitely have a coldframe full of spinach, leaf lettuces, etc.
I've even tried putting tomatoes out in late April here, but it never works out. Milk jugs, polyurethane, etc. Big hassle. Fact is, around here, if you put them out in late May they quickly catch up to the early birds, and even exceed them because they have endured no cool weather stresses. Tomatoes do not really put on growth without warm nights - above 55 F. We are still in the 30s on some nights.
If you have money to burn, the best thing is a good-sized real greenhouse. I would attach one to the house, with interior and exterior doors, so you could just open the door and let the rich earthy and flower and herb and plant smells infuse the house. Home-grown Beefsteak tomatoes 12 months/year.
Pic is Beefsteaks, the only tomato I truly enjoy eating, especially when hot from the sun. We usually only get a few weeks of them ripening, mid-late August-early September. Is it worth the trouble? For me, it is. It is especially pleasant when you can find a big ripe one that a squirrel or chipmunk has not taken a bite out of.
Here in California's Santa Clara Valley (San Jose) my peak gardening experience was a ripe peach that fell into my hand one hot summer afternoon. It was over 100 degrees and the peach radiated peachy aroma. Once pierced by the tooth, it exploded in hot, fresh peach juice in the mouth.
I grow produce under adverse northern conditions. Greenhouses and coldframes are too expensive and too much fuss.
Biggest bang for the buck for warm season crops is floating row cover in the garden. It's a light synthetic fabric that lets most light and water through.
Air and soil temperature under the fabric is considerably higher than ambient, the cover will gain a couple weeks maturity over uncovered. Keeps insects out too. If cared for the stuff lasts for 5-7 years.
Here in Israel greenhouses are used to keep bugs out rather than as season extenders. These are just frames with thin plastic sheeting. We export a lot to Europe and they have very strict pesticide regulation - so this is the solution. Also insures good quality cut flowers.