I JUST went through this. DS2 was also sleeping for a really long stretch until he got sick, then he started waking every couple of hours to feed. Even though I knew he wasn't hungry, I'd feed him because I was too tired to think of doing anything else. I guess that's what happens when you lack a plan. I did the whole "pick a time to feed and don't feed him before that" thing and it worked for us. Kind of. I executed it a little different from the intent, I think, but now we don't have any NFs! He gets a DF at 10:30pm and then nothing until 7am. Of course, I'm sure that it will change now that I think I have the hang of it, right?
Anyway. I just planned not to feed him until after 2am, so when he woke up at 1am, I resettled him using shh/pat. The next time he woke, it was feeding time. Yes, it may seem like it should be confusing for your LO, but it worked. It certainly reset DS2's tummy and his wake-up clock.