I started a greenhouse grow in aug while 54º north. Any hope?

So i got a bunch of black sugar seeds and have 4 happy looking seedlings. I'm growing in the conservatory which gets sun all day. I've done a grow under lights and a guerrilla grow before with good success so i know this is very far from an ideal time to grow but its now or never. I've got access to some cfl's and in theory a 400w HPS and MH light but i'd rather not get them outta the attic.

My question is, is there anything i can do to make this work in any way or is it just gonna be a nice little house plant that never becomes smokeable? Growing in soil.

thanks folks
Sam