I succesfully white-peaced out (had no intention of winning) after 2-3 years and I've fully won it in the past without ever doing the Bearn strategy. In 1.9, Englands economy is very good. I started by making cogs until I had 25 of them. Use those to launch quick assaults on enemy sieges to annihilate small (<10 units) stacks. Watch out for nearby doomstacks, of course. If every siege has +10 units or it can be quickly reinforced, try to find the weakest spot and assault them there. You got 25 units with a good general so most of the time you should (barely) win it. The other enemy side will often reduce their siegestacks to go help the side you assaulted, so load on transport again and assault that side. Basically, play pingpong
this was enough to get white peace (1 month before War of the Roses triggered), if you want to totally defeat them and PU them, pray that Burgundy will attack them around 1449ish while you deal with War of the Roses.
There are probably better strategies around, but this strategy worked for me first try and I quite enjoyed it
Good luck!
Edit: To provoke them, try to siege a province like you did. Sometimes their full stacks were at one side, so I just started sieging Ile de France or Bearn. After a while, they would move most of their stacks to me. Don't really know other ways, but perhaps reloading to trigger a new calculation might work
Edit2: Oh and get a diplo advisor and invite Portugal in the fight day 1. They can take care of Hungary and earn you some warscore