i would say manatusk strains would be ideal, i have the thunderfuck(more indica) hybrid as permitted by WA state DOH for my personal medical consumption, and then theres manatusk mint.
manatusk tundra is a linear strain from, manatusk alaska. there is a sister strain as well, but they are built to last in 60-75 easy, they stay minimal with the leafs and stand around 4' tall, with dense bud formation.
because of their alaskan heritage they are accustomed to rich soil/heavier nutrients.
also, the NL strains should handle some chilly weather and maybe show off some more color because of that. both manatusk and northernlights stay squatty and yield in 55-65 days, even with some sativa thrown in.
the lower 40's would be pushing it, because of this it seems one would have to be extra attentive to other factors, but all MJ plants really like a 15 F decline over night, so if that worked in the equation it could be nice, the growth will be slower for sure, but all is good with patience.
they would need to be popping soon if seeds to ideally veg through out this shorter sun cycle.