Well, I actually started out at 6mg on a cig-a-like back in Oct. While it was not great - it did get me down to 3/4 cigarettes a day. I then found ECF and realized that I had started with way too low on the nic and that there were much better devices to be had. I was smoking a carton a week of extra mild cigarettes when I first tried vaping to see if it could help me cut down I actually had no intention of quitting
So, I ordered an eGo Twist kit and some 18mg juice and the day they arrived I did not even have the one cigarette a day I was down to. Found I could barely tolerate that 18mg juice so I lowered to 15mg on my next order. I stayed with that for probably 2 months and then lowered to 12mg.
At that point I got started in DIY and I started mixing at 12 and 10mg. So right now I actually have a fair amount of 12mg and 10 mg and I rotate thru these depending on how I feel. However, I am finding that most often the 12mg is to high now and I can only vape it for a little while and then I have to use the 10mg. So today when I mixed up a new flavor to try - I actually made it up at 8mg. So probably two months at mostly 12mg and the last month at mostly 10mg.
For a short time I did wonder if I actually even needed the nic - or if it was just the habit. So I mixed up some 0 nic about 3-4 weeks ago and just vaped that for a day. Found that while I did not crave a cigarette - I was generally pretty cranky and felt out of sorts for most of the day. However, I did find out that I do still need the nic - but it does seem like I am able to keep lowering without any major issues.
I too am not sure what will happen or if I will even get to 0 nic so like the OP I will just have to see what happens when I get there.