Haha, actually I did rope in a friend or two to help me move, (one of whom is an avid CK2 player, and did also give me some good advise on this).
As an update, what finally happened:
Queen comes to the throne, and we do the whole divorce-dance. Get about 6 months before a gigantic rebellion, which shows half the Dukes revolt. Halfway through, the Queen of Scotland decides she wants a piece too, and brings in France (which is in the middle of its own massive succession crisis so not too bad.) I beat off the rebellion, and the new levies help me fend off the Scots. She actually peaced out with a surrender at a very low percentage, which was nice!
As it turns out those wars took 5 years to complete, so I was halfway to my target already! Then my queen gets sick. And she stays sick for a very, very long time. I'm literally sat there in terror the entire time. Eventually, however, she recovers. I do a bit of invading (Ireland), and generally focus on ensuring nobody is angry with me, for when the time comes. I get to 1 year before I can change, and am convinced I'm going to make it. After all, all she has to do is survive one more year, right?
"I'm sure my husband will be pleased, I have potentially-lethal parasites inside me!".
Those 9 months were nerve-wracking. Eventually she gives birth to *twin sons*. My first children of my dynasty! At this point, I wait until the 10 year mark, then attempt to murder my eldest, non-dynastic son. 3 attempts, 3 failures, and I got caught on the last one. I've thrown away almost all the gold I got for ransoms, so can expect a reprisal soon, so I swap to elective and vote for the most capable vassal of my dynasty. Should be interesting to see what happens next, but at least I've managed to survive!
tl;dr changed to elective, managed to survive. So very, very happy
Next up - ensure Normans survive so I can do the culture conversion to English.