I think it depends on how your body reacts. If your immune system is overactive, it will probably go back to attacking but it will take a few months for the drugs to leave your system. I have stopped 6mp for a month or two and I didn't have any negative side effects from stopping it, I didn't flare up either but I never intended on stopping forever, it was just temporary until my WBC recovered. I don't like the idea of being on these drugs forever either. Hopefully there are some better treatment options available in the near future. It's possible you will be able to remain stable with 5ASAs, have you tried any? I flared while on Asacol - it seems pretty clear in my case that it was no longer working well for me.
It is a bit risky to stop Remicade, I have heard people say it is not as effective if you use it again in the future. I have seen a few people who were able to stop and restart it successfully as well.