A milestone, but how far away is the end game?

I passed the 100,000 words today in my first draft!! (Working Title - Last Kiss)

Mind you - I still don't know what the whole plot will involve. I guess I'll have to trust the process.

Yesterday was a bit of a marathon run for me, getting over 3,000 words done, and I think I'm paying the price for it today, but still, I'm reasonably happy.

Apart from the finer details of the plot, and how it will all end, I can't put an estimate on how far away the finish line is. 

It's close, but how close is the question??