Point A: Shenyang, Jilin, China
Point B: Plymouth, Massachusetts, United States
I found a delightful report the United Nations put together in 1994 on how to produce crops and energy in the cold northeast (42 degrees north of the equator). It's got a wealth of information on topics from methane production to solar homes and greenhouses, and integrated plant/animal ecosystems.
It's also chock full of charts and graphs and experimental results.
The full title is "Integrated energy systems in China - The cold Northeastern region experience."
Happily, the cold northeastern region of China is eerily similar to the cold northeastern region of the United States - same latitude, near an ocean, and populated by millions of folks who like to eat and stay warm.
I particularly liked the documented results from the experiments comparing Subterranean heating/Cooling Systems or Underground Heat Exchange Solar Greenhouses (UHESG) to Conventional Solar Greenhouses (CSG). The 1980s-era researchers document greater than 50% improvement in yields (in both weight and money value) for UHESG over CSG.
The English in the report is a bit awkward and laden with engineer-ese, but there are plenty of great ideas for those of us who have uncomfortably cold winters.
[Post Script - Latitude isn't the only story. The hardiness zone in Shenyang is between 4 and 5, while the hardiness zone of latitudinal twin Plymouth is an ocean-warmed 6. Due to the Gulf Stream, London enjoys a hardiness zone of 9, though it is almost 10 degrees further north than either Shenyang or Plymouth. I'd have to travel south to Florida to get to a hardiness zone of 9!]