House is 75' wide in the front
House is set back 70-80' from the road
Lot is at the end of the cul-de-sac (trapezioid shape)
The narrowest diameter circle I recommend for a circular driveway is 50 feet. At this diameter, I tend to make the driveway at least 15 feet wide sometimees 18 to 20 feet. This is because the turning radius gets too tight for larger cars and impossible for delivery trucks. Will a U-Shaped driveway work? You are certainly close enough to the road for this type of driveway. The space you are describing to me sounds better suited to this type of driveway. One possibility is to enter at one side of the property, let the driveway bring you to the front door where the driveway would be at least 18 feet wide, and exit at the other side of the property.
Hope this information helps!
Nancy