Leanne
The ferry leaves at about 6.30pm and disembarks around 9.30am on weekends and an hour, or so, earlier on weekdays. We generally go to France in September - we are off there next week for 5 weeks! It is very warm then without being stifling. I would imagine that it will be much hotter and busier in July. We stay in Vaison la Romaine in Provence which is a lovely town and quite central for Orange, Avignon and Nimes. There are aslo lots of interesting places to see 'in the hills'. There is a site in the town ' Camping du Theatre' from which you can walk into town but it is always busy and you would likely have to book for July. The site is always crowded and quite dark in places under trees. The upside is you can easily walk into town. We stay at a site called 'Camping Le Soleil de Provence' about two miles out of town. It is bright, airy and very spacious. I've never been in July so cannot comment on how busy it might be. We always take two easy days to travel. First stop is at Chalons en Champagen at 'Camp Municipal', with the second night at Sennecy le Grand at 'Camping Chateau de L'Eperviere' Both are excellent sites with the latter being a good base to spend a few days in Burgundy. Looking at the map a half way stop may be about Beaune or Chalons sur Saone, but I don't know any sites there. If you don't already have it, I would recommend that you buy the Caravan Club's 'European Site Guide Handbook'. You don't have to be a member to get it as it is available from the likes of Watterstons. If you do think about using the Hull ferry and are flexible with your leaving dates then check each day around the time you want to leave as the price can vary quite a bit. Normally the weekend dates are the cheapest. One thing about arriving on a Sunday morning is that heavy goods vehicles are largely banned from the motorways on that day so you zcan often make better time.
Hope this helps.
Lawrence