Re: bsf in PNW.... I have just done some research and am tossing this idea out. It seems that larva can be kept warm
enough with insulation and their self-generated heat to possibly survive our winters and continue 'eating'.. at least, as far north as Eugene. Its the mating/egg laying that has to be done in light, and at around 70 degrees, which is why buying in larva every year may be necessary.
However, it may be possible to take some (a few) pupating larva inside, buried in a tray of minimum 2" of soil, let them hatch into flies (which are slow moving, live less than 2 weeks, don't eat anything) which mate and then lay eggs. I believe they can be easily contained in a small screened cage, with enough light and warmth. Apparently they readily lay eggs in edges of corrugated
cardboard daubed with some foods (can't remember, but can look it up if desired), or, best with exudate from the bottom of the larva feeding container. The hatched larva can be sent off to turn into feed. This whole process happens pretty quickly, btw... raising larva through the winter and to increase larva numbers.
I got this information from talking to the largest larva seller, in one of the Carolinas... who, coincidentally was backlogged on their orders... which I take as a good sign of something ;)