I think that's exactly right. The "range" on electric cars is best case (no radio, no climate control, being that dick who won't accelerate on the on-ramp, etc). "Half" is probably a good engineering fudge factor, and a 40 mile practical range doesn't cut it.
You are WAY underestimating it.
I honestly have not driven my smart to absolutely empty, but I do know that its range is very conservative. E.g. I drive 20 miles, and it only takes off 15 miles from the range estimate after that. So I end up going farther than it says when 'full', which usually is in the low-mid 60 miles. (I think the official range is 68 miles.)