I have not tried it on my C-Max yet, but on previous cars, namely my 1983 Celica autocross race car, I would put the jack at the balance point. In that car, it was just barely in front of half the wheel base. The C-Max is a bit more nose heavy, so I would guess about a foot in front of middle of the wheel base. To reduce stress on the car, I had a foot long 2x4 with a slot in it that I would place over the body seam and put a floor jack on that, it easily lifted both tires without hurting anything.
I have also run mismatched tires on the same axle, both front and rear on cars with ABS and traction control and it has not been a problem. As for ABS, when you roll straight with no acceleration or deceleration, it sees the different speeds and uses that for the base. I tried it on ice and the ABS worked fine. I would assume the traction control does something similar. Worst case would be less accurate control when you do lose traction, but let's face it, if you were driving on a mini spare, you will be taking it easy anyways. The only cars that have an issue with different tire diameters for even low speed careful driving are mechanical limited slip systems. Any speed difference at all will cause the clutches to be constantly slipping and getting hot and even wearing, let alone the pull it will cause, even just coasting. I had an Eagle Talon AWD, it's "mini spare" looked like a frisbie. full diameter, but only 4 inches wide.
The different diameter can cause a slight pull under braking, but if you are getting a strong pull, it is more likely an offset problem. The center of the tire is not the same distance from the center of the steering pivot compared to the tire on the other side. There is normally some offset, but since the two sides match, the torque induced in the steering is cancelled when the offsets match. even perfect diameter can cause a strong pull under braking if the offset is off even a half inch. But again, we are talking an emergency spare to get you to a tire shop. Drive a bit slower and carefully with more following distance while on the mini spare. That should be the rule any time and in any car when on a mismatched tire.