I think there is a window with potty training, and it closes before age 2. If you miss the window, then you are looking at a child that WILL be in diapers until age 3. It will become a power struggle, and you'll end up having to wait for him to make the choice.
We used Elimination Communication, and my boys were both out of diapers before 18 months, day and night.
Now that being said, your daycare lady does NOT sound very understanding. Now if she's so adamant that he is trained in 2 months, then tell her that she needs to get on that and start the traiing process during the day when he is with her. You cannot train him in a weekend, or in a day when you are off, you need her cooperation to get it going as well, and while I think her threatening you is absurd, if she starts, he will follow suit because its HER doing it, he will follow her 'command' so to speak. Plus I'm sure there are other kids at the daycare who are trained, and he will get excited about going to hte potty with the big kids.
BUt if she's not on board, and expects you to do it all in a weekend, then I'd be looking for another daycare because she sounds unreasonable. If sh'es willing to work with you and help get the process going, then go for it. No reason he can't be trained now.
And it won't happen overnight. Set a timer, take him to the potty every 1/2 hour, go with him, help him. Hes not going to be able to go by himself or tell you that he needs to go, its your job to take him and keep him on track. This is new to him,he's been allowed to pee in his pants for 2 1/2 yrs now, you can't just turn that off. He needs to re-learn how to use those muscles again to control his bladder (babies are born with the muscles ready to go to control thier bladder, but lose them over time when allowed to be in diapers for 2+yrs).
So you need to help him, take him every 1/2 hour until he starts being consistent, then stretch the time out. Set a timer, reward him with your praise and new cool big boy undies. Make it fun, stress free, and talk up the big boy aspect, but you have to help him, with his pants, taking him to the potty, etc.