From memory, Motability stopped people ordering by phone due to complaints from other dealerships, but as @kezo says, it’s worth a drive to Portsmouth (if you are able) even if you have to go twice – once to order and once to pick up.
You could turn it in to a mini-break. Portsmouth Historic Dockyard is very good (the Mary Rose particularly, which is fully wheelchair accessible) and nearby Gunwharf Quay is a discount shopping village with lovely waterfront views. There are loads of nice pubs and restaurants there and in Old Portsmouth. The £1,000 saving would pay for the two journeys, mini breaks and still leave you with around £500 in your pocket! If you were feeling adventurous, you can even pop over to the Isle of Wight!
