Sorry to hear that your wife is set on a D SBJ. My H also expects us to D one day, but since I told him I am not going to file we have to actually wait two years after a separation for an "amicable" divorce (if we both agree), or I can even refuse to sign and then he can "automatically" get it after five years. Horrible situation, but it was the only way I could think of in order to buy myself some time. I'm not advising you to do the same, I don't know if refusing a D for a period of time will help at all, I guess I'm just hoping that he might be nearer the end of his crisis by then and something could change?
My H told me the same thing, he wants to do his own thing, he doesn't want to be a "yes man" any more. So sorry you are in this situation
Take care
"There's nothing sadder than a conman conning himself"
“There is freedom waiting for you, On the breezes of the sky, And you ask "What if I fall?" Oh but my darling, What if you fly?”