I really can’t see why they wont let you have a 24 hour Test Drive- it can not be an insurance issue, otherwise no one would be able to have the use of a loan car when their own car is in for repairs or servicing !
As far as room is concerned, it is lower than my previously car ( Tiguan )both the seat height, and headroom and is narrower in the cabin, but I am 5’10” with restricted movement due to my bottom half being held together by steel plates, rods and screws ( never argue with a parachute, it will always win ) and I can get in and out quite easily!
The doors open wide, especially the rear doors, and the boot is a reasonable size with a flexible floor!
Hope this helps!