yes it would work, if you did it consistently(thats how we do it indoors, put them in the dark for 12 hours). You would probably going to need to do it for a week or so though. If its not consistent, and you bounce the photoperiod around you can develope hermies.

In my opinion it would be the smart thing to do. I live 100 miles south of Vancouver BC and at the end of September im fighting mold and rain. The faster you get the plants to bud the better, who knows if theyre even gunna finish. Frost is even worse though.