I would recommend lighting.
Look, just because you can shoot in low light, doesn't mean you can shoot in no light or that you shouldn't be lighting.
You will eventually approach the limitations of the technology you're using, the medium, whatever it is. So, you'd want to use a good ISO to properly expose the background lights, something like 320 should be ok for this in most cities. Maybe 640, if you need to depending.
You'd want a good fast lens, though not to open up and shoot WFO if you can help it as the lens's performance will be compromised. You'd want to aim to be around a 2.8~5.6 somewhere in there.
And then you augment the light around you.
So, for that I would look into some small units you can move around easily, probably battery powered as I am assuming you're run and gun. I would try to backlight whomever I'm shooting to separate them a bit from the background, give them a nice little rim. I'd always also want to have a bitch of a catch light in the eyes at night otherwise you're filming a skeleton basically. Something like a few small LED light panels can work wonders and cheap. I picked up a little one for $100 on a shoot out in Vegas and it's ugly as sin, greenish, and not what I'd normally use, but it's small, battery powered with AAs, lasts a long time, is dimmable, and would be perfect in a "low light" situation just to make sure I can see who i'm filming. Throw some 216 on the front of it to soften it up and call it a day.
Now yes, shooting WFO will give you super shallow DoF, which is great and all, until you try to keep things in focus. So you better have a good AC to pull for you. If you don't, you'll find you're mostly looking at blurs.
My 2 Cents.