First, what is the ambient temp where you are bottle conditioning (take a temperature reading on the glass of one of the bottles)? You want them around 70 deg F or so, and given the frigid temps where I am I figured I would mention that first.
What was the OG of the IPA? If it is a big IPA, carbonation can take a while.
As far as going from bottle to keg and force carbing, I suspect it is doable but you have to be very careful regarding exposure to oxygen. Your best bet might be to fill the keg with CO2, sanitize some really long gloves and the outsides of the bottles, and reach down as far as you can into the keg to pour with as little splashing as possible.