By doing everything you can to not get in a head-on. Ditch it, land it in a yard, etc. Just about the only thing I wouldn't do is dump it in a flooded ag ditch, but that's a situation most people don't find themselves in. If you're in a city where you have literally nowhere to go, nobody is going fast enough to the point where the size differential between the vehicles is going to matter unless you're in something exceptionally small.

There are multiple times where I've had to drive on the shoulder to avoid people out of their lane and they would have been a hell of a lot scarier than they were if I had to do it in an SUV/truck. I've been in multiple fairly severe vehicle accidents and I can tell you from first-hand experience that you're not appreciably safer in an SUV.