GO FOR IT !
if you have the dream, if you have the money , there should be no hesitation. But it doesnt need to take you 2-3 years. I just did the 7 Zummits in a little more than 6 months. You can try to do it fast or you can do it a little more relaxed, say 1 year. But soon you can be back at work, if that concerns you. But I tell you, the coming back to work, sitting at a desk, looking into the PC is bad ! I think I have a depression, and my thoughts are longing for the mountains ! Thats the biggest risk
To quote another Dane, Søren Kierkegaard: " courage is to let things slip for a moment, not to have courage is to loose yourself forever"
I left work for 9 months to follow my dream of scaling Everest and the 7 Zummits, and as I said now I am back in the rat race. With the present state of the world economy you can get ajob anytime, even if you are out of circulation for a year.
Get your ass in gear !
Best regards