I've always waited in the line and when I got to the steps next to go in they directed me around to the ramp and I parked the ECV and walked in. I think an electric WC could maneuver in there but in my mind it seems too small for an ECV to get through. I've not seen anyone take their ECV in. I wonder if you could call them and ask? ** their website says you can't call but they have an email webform for questions here:
Email Gideons. Click on the bars at the top right of that page then click on Contact Us on the bottom right of the next page.
I got an assortment of flavors for my family - maybe 6 cookies? Wooooo...they are expensive!