i'm sorry to hear about the talipes - hope it all goes well.
It's a million dollar question for which there is no answer! All babies are different. My ds is 12 wks old and still waking up thru the night several times and I think he is doing well to reach the 2.5 hr mark bet feeds during the day.
If your LO is doing 2-3 hrly already, my guess is it will improve. Babies wake thru the night for many reasons - feeding is just one of them. And if your LO is used to co sleeping, the transition may be difficult...might be an idea to do it before you have to?