HEY SURFER BOYS, people live outside of California.
There are several of us who grow outside of zone 7 here. Moving your plant inside in the fall sometimes is the only way we can survive a -2C overnight in late August. Happens here all the time, granted I live a zone or 2 away from the tundra.
Very rarely do we get 10 foot cannabis trees. Even with sunlight, and lots of it 20+ hrs some days. Without that constant ability to move our plants they would never reach maturity, so they usually stay in pots and simply slide from their night spots, living room and slide out to the sun deck. Making sure they face the same way each morning.
I tried to avoid supplementing the light with the hps, but snow came early the one crop so they finished there with a light over them. Kinda stunted them, well retarded them, slowed the production but not the process, the big 2 last week girth didn't really show, skinny buds but were ok.
I would not try going from sun to straight hps/led/ what have you. They really noticed the difference sittin on this side of the patio door, so a straight grow room would likely really retard it.
My grow mentor says never try it, the sun is the best light, and they don't like to settle for second best when they've had the real thing. So I try to keep them in the light as much as possible, and yes the portable ones out perform my 1000hps indoor crops everytime.