She's eating 2-3 large rats a week right now. Got some XL rats and some XXL guinea pigs for her next. Ordered a box full of large and she outgrew them in a month. Just started feeding multiples. I measured her last night at 8' long.
I haven't found a way to keep the humidity above the room humidity in a screen top aquarium. When they get close to shedding (eyes clear and that feel to their skin) I soak them every night in the sink and get the aspen substrate saturated in about half the cage. It won't mold because it dries out so fast.
If you're going to leave the snake in the screen top acquarium I'd suggest getting some sort of sealant (like that rubber in a can on TV) and sealing most of the screen. That will help stop some of the humidity loss.
It's hard for me to do that and make it worth while because I use ceramic heat lamps on top instead of belly heat on the glass.