Mark,
From recollection of my last visit for the 100th anniversary event, that road is wide enough. The aircraft does not need a lot of runway to land, from what I have seen before. I understand it is registered on a US experimental registration and flying time is restricted, hence why it is coming to Brooklands for its final flight. Saying all this, with the weather at present it would have to dramatically improve overnight, I would have thought.
Keep an eye on that forum link as they seem to be in the loop as far as aircraft happenings.