Hi
@DSGDSG6 and welcome to the forum.
A Harbor Freight greenhouse in central CT will be very expensive to heat. If you don't heat it, you can get a jump on the growing season, but a greenhouse with no heat, heat storage or insulation will only stay a few degrees above the outdoor temperature once the sun goes down. A Harbor Freight greenhouse offers almost no insulation. Most out-of-the-box greenhouses, even though they are advertised as "year-round", offer very little insulation and are not suitable for northern winter growing "as is".
Tropicals in a GH in central CT for the winter would require ground insulation, east and north wall insulation, perhaps a ground to air heat exchanger and supplemental heating as well...in addition to glazing that has a high insulation factor. You are talking big bucks...a very expensive pre-made or custom built.
