Okay, so, theory time.
I don't see Rinnosuke waking and going "Oh, you clocked me? I guess that means I lose then" and undoing everything, so we still need to find a way to deal with this for good.
If Nue's metaphorical debt wasn't sky high before, it sure is now, and if he wakes up and we're around him, there's no telling what he's capable of doing to us. We're a danger to everyone around us, and Gensokyo as a whole, as long as this issue remains unresolved. Never mind that, evne if he doesn't enlist us for whatever other slavery he can think of, he could probably just drain our natural shapeshifting essence now that he's lost control over the cards.
At this point I believe we need to stash our cards in a safe location. We can defend ourselves; they can't. The ideal location is less one where he has no idea where they are and more where he or anyone else he enlists has to put forth maximum effort to retrieve them. Interesting to note is that he considered the cards his legal property after he paid for them, a personal philosophy we may be able to take advantage of. We can also help ourselves by enlisting the aid of someone that rarely-if-never interacts with him, because he will have no debt control over them. This leads me to two plausible people to whom we can trade our cards (however temporarily). The first is Shuuei, for fairly obvious reasons, and we have the added bonus that Nue would actually think of her. The second, and I can see Guy jumping up and down in excitement over this, is Satori. I would imagine she has never had any dealings with him, he won't be able to sneak-thief anyone by her, and she has big pet guns backing her up should he try a more, uh, direct approach. (Not to mention a city full of oni who will probably be more than glad to rip in half anyone they find trying to steal in the name of the person that stole all their money.) Nue knows the second and the third for herself, and I don't think it unreasonable to inquire into the first one. Trade all of our cards to either of them for a door prize and a promise that they never hand the cards over to Rinnosuke or anyone claiming to work for him, and they should be safe for the duration of this disaster.
After that, we can maybe play hide-and-go-seek for a while, or consult with some powerful minds, or maybe the tengu will finally relent and let us through to two of the best people equipped to handle this situation. But we can deal with that as it comes, because we're Nue Motherfucking Houjuu. We'll probably want to get in contact with Ran again, though, since Patchy(?) dropped Yukari's name under "if she were awake this would be solved already". We don't necessarily have to worry about solving things permanently; just for long enough for her to wake up, and she'll take care of the rest.