Hi mhedges and welcome to the forum
The "problem" with short trips with _any_ internal combustion engine is that its not up to "efficiency" until its fully warmed-up. Summertime takes 1 mile or so. Wintertime closer to 3.
During the warm-up period MPG's will be much lower. As a percentage and especially in a 5 spd Insight (no lean burn 'til warm) the MPG "loss" appears to be astronomical. But it is a similar percentage for all cars.
Under short commute conditions in warm climates expect an attainable (with effort) annual MPG average to be in the upper 40's. Cold climates mid 40's with the CVT (automatic transmission) Insight coming in a bit less then 10 MPG lower.
As far as the IMA batteries, shouldn't be an "issue" if your driving for maximum MPG for the available conditions.
I don't think any other _gasoline_ car in production could come close to that MPG under those conditions. But a diesel might.
HTH!