I did SDW last year assisted by Trailbreak. Winchester - Eastbourne about 97 miles or so. 1st day was long - about 60 miles - stayed at truleigh hill youth hostel. They have camping I think outside the hostel so you can probably feel a bit safer there. Might be worth contacting them.
The next day was hillier but went by a lot quicker.
Hope this helps. It's a fantastic route when the weather is good which it was when I rode it.
Good luck!