At the end of the day I think it will come down to the comfort. 
Planned one route, Sheffield, London, Birmingham back home some 360 miles but maybe sitting waiting in London (Heathrow) and 6.5 hours driving, 60 MPG or better would be nice.
So still no rush. Plus age maybe easier access in and out for car maybe puts the SUV's higher on the list.
And possibly Sat Nav if you think Heathrow and Lundun are the same place

Joking aside 60mpg + SUV = fantasy...
You'll die of boredom long before it gets close.
Also, ease of access is a customer consideration. Being sat in the back of a jacked up Golf (aka Tiguan) for 6.5 hours may not be conducive to passenger comfort.
Our opinion is just that, opinion. They only way you're going to be able to answer the question is by going and looking. Find a suitable Car Giant type place and try anything that might be a candidate. Then buy it from somewhere else.