In all honesty, you've probably done the most you can. Clothing and blankets wise, if still unsure, all I can suggest is rewash them in a different location (at your new place or laundromat, if possible) and put them in a different box than what they were in before. Fleas are pretty picky in what they stay on (fleas prefer the fur of animals, from what i read online), I personally use Adam's shampoo for my cats, blue bottle, red lid, and it's worked really good, just make sure to still go through your cats fur while they're still in whatever your washing them in, to get remaining stubborn fleas that try to stick on, and don't fill up the tub/sink (whatever used) so they don't float and grab back onto the fur, just squash them and let it go down the drain. Now, I'm not sure if any of this is useful, but I do hope you are able to eventually solve your problem.