It's a bit warmer down here and I put the toms out in pots against a sunny wall, and under plastic sheeting for the first few days!
For a few years now, I've been planting two per 10" pot, in a watering tray (8 plants per tray), and the yield has been pretty good! The greenhouse plants go in the same way and watering is a doddle!
I'm trying some Roma toms both inside and out, and up strings, although the yield may be slightly down they're worth a try! (I was given the seed by a chum as she had trouble getting her toms to germinate, so I became a 'surrogate' Tom..:0)