Jax, your advice is a bit above the paygrade of someone like me.
Uh huh - so as always budget is important

That being said, having some idea of what your budget
is can be useful - you may not know how to use an HMI for example, but you might be able to swindle a good deal with a Gaffer who does, and owns them, who just doesn't have any work on at the moment (I've been able to negotiate Gaffers who might normally charge $1k+/day to come down for 1/10th of the price, and in some cases just for petrol money because they have no other work on, or because they're a friend of mine).
But, let's assume that's not happening - as you say your budget is basically nothing.
- I have Arri knockoffs, 2x1000 and 2x650. I also have 3x1000 led lights. and 6x300 led lights.
- This is going to be shot in a residential apartment, and so no outlet can have more than 1.5k coming out of it or the breakers will probably fire.
Cool, how many circuits are there? I.e. how many lights can you have going at once? Are the LEDs running on battery?
I'd probably think about using your 2x 1k's as your 'moonlight', if that is indeed the effect you're looking for - gel them blue and shoot them through the window. Then I'd use your LEDs at varying levels of intensity and with varying levels of diffusion to help shape the light one the people themselves - your 2x 1ks are going to light the bg quite well, and may or may not do what you want with the people themselves, but having those LEDs, assumedly on battery power and easily maneuverable means you can do what you need.
Use your 2x 650's as your 'pre-blackout' tungsteny light.
Of course, there's all sorts of things you can do - but to get you thinking about it, that's one solution I might think about.
[Edit: What I was really planning on doing was shooting the lights up at reflectors when 'lit,' from all sides, and doing the same when 'not lit,' from only the window side, with the lights just a little dimmed. I don't have the knowhow or the skills of hanging kinos/led lights from above. I was thinking having reflectors above would have a similar effect.]
Reflecting the light will certainly soften it a fair bit - where they're sitting/what angle and whether you're using a silver reflector or white reflector (white will be softer) will determine how much.
It's certainly not a bad idea - I'd give it a bit of a test beforehand to see if you like what it's doing before you lock it in.
My only concern might be having it look a tad flat, which is simply not really my kinda style, though it may be totally what you're going for. As always, it all comes down to taste and what you want.
I'd also suggest buying some sheets, or a roll, of diffusion - it's pretty cheap; I've even seen people use bed sheets and shower curtains to diffuse lights on super low budgets.
You could chuck 1 or 2 1ks out the window with a shower curtain in front, so you're just getting a glow from the window in whatever colour you gel it to (maybe blue for moonlight, or some kind straw/CTO for street lamp). Then shape with the LEDs.
Good luck, have fun!