I believe 1/2 q is the ideal increment to add, as you only have to mess with an open bottle once. So, I say reset the odo and use a predictive method to get to that point, be it 500 miles, a 1000 or whatever.
It took a while to get used to the Hondas, which did not burn oil. Now, I think it would bother me if I had to add more than 1/2q between changes.
SO far, consumption has been minimal in the Tiguan, in the Astra...it burned a little bit of GC over the summer. Topped it with dino.;0)