The Anglian ice edge environment in Southern England

Back to this map again -- which seeks to portray the glacial and "pro-glacial" environments of Southern England at the time of the Greatest British Glaciation (GBG). 

One of the greatest problems we have is the sheer age of the deposits left behind from events that happened c 450,000 years ago -- there will be very little left of them, especially where the glacier ice came and went again within a few centuries. (In contrast, in Eastern England the ice seems to have been in place for a much longer period of time -- probably several millennia -- leading to the deposition of quite thick tills.)

Another problem is that it is very difficult to imagine what this ice marginal zone might have looked like, since all of our analogies from present-day glacier and ice sheet edge environments show us what happens during the WANING (wasting) phase of a glaciation.

I am pretty convinced that when the Anglian ice moved in towards its "maximum" position, it would have been impossible to see it, because the whole of the landscape will have been covered with perennial snowfields and (over the higher areas like Dartmoor, Exmoor and the Mendips) thin cold-based ice caps.

Does anybody know of any evidence that might disprove this hypothesis?