If you're not looking to squeeze Lady Richard in the back (she may not appreciate it) then I'd be tempted to try and find a Twizy Cargo. You can fit more shopping in there securely and away from water.
I struggled to even get a quote (££ or delivery time) for a new Twizy, most Renault dealers around me didn't want to know, even going as low to lie saying Renault don't make them anymore.
My advice would be to start with Renault customer services (although they're not the best either) but they have a tiny bit of sway on the franchise dealers and they know where the current stock of Twizys are.
I ended up finding a year old, 34 mile old ex demo Twizy for £5k.