It's a shame, but it would be scarcely usable. I'd agree with your estimate of the lot being about 110, maybe 120 feet wide.

The problem is that if it's 110 feet wide, you lose 25 feet minimum on each side due to hard curbing. That gives you 60 feet in the middle to work with. And everywhere there's a light pole, you have 55 feet between the curb and the light pole. To be technically even barely legal, you'd have to have 25 feet on both sides... leaving you a 5 foot wide course.

Even if you can fudge enough space between the light poles and the curbs, about all you could do here would be a glorified slalom. Not bad for an occasional event, especially if the site is cheap or free. But not a serious autox site.

Think about how much people complain about the SPC site that the Sunriders use. It is 600 feet long and 300-400 feet wide. 120x400 is not much to design a course on.

Now, I've seen autoxes run on an old airstrip that was 150 feet wide, but it had grass on both sides, so we could use ALL of the 150 feet of width. It was also 1/3 of a mile long!