Halt the grow for longer veg?

When growing outdoor up north the autoflower doesn't start to flower after 3 weeks, it's obviously too cold at night so it takes some more weeks before they start to bloom.

So what I want to try is to copy the nature in a grow tent by keeping the temperature down the first weeks from some days after the germination until they start to bloom, at the same time I'm gonna give the plants lots of light(but I need to avoid the high temp so I guess LED is the only option here)

Low temp and high amount of lights is how to grow strong tomato plants, can it work for autoflowers so they grow strong and get deeper roots before they start to bloom?
And how low temperatures can be used without giving the young plants irreparable damage?
Can 60F/15C work?

And of course, after bloom starts the temp will be set to normal

 

[c@b420]

I'm not sure if that would work or not. Autos have an internal timer. The colder it gets the slower the growth which is true, but isn't something you'd really want when it comes to autos. You want fast and vigorous growth with the best conditions possible.

if nature is illegal, freedom doesnt exist..