Is it just you coming to bed? In other words, would he sleep all night if you weren't there? Maybe you could have him in sidecar arrangement, or on a smaller matress beside your bed. But then if he will not sleep past a certain amount of time whether you are there or not, it may not help.
I agree, hard as this is to hear right now, that it's almost certainly a phase. Your son doesn't need to be "trained" any more than my DD did (she never went through a "needs boob in mouth all night" phase).
Personally, my threshold for nightweaning is pretty high. I waited until DD was showing signs of readiness (popping off the breast before being fully asleep, turning over and snuggling to sleep) before we started. She will be 2 next month.
Most of the gentle weaners like NCSS and Dr. Jay recommend waiting a year. It is entirely possible that your DD needs to nightnurse (maybe not with a nipple in the mouth all night long, but enough that nightweaning would be detrimental).
Anyways, the thing to do is give it a try and see how baby reacts. They will let you know right away if they are ready for it or not. And we must honour that as parents. We wouldn't try to force them to ride a bike before they were ready, as it is with other things.
Good luck!