Might be a bit late in the day for this year but would really like to travel up through Western Isles (Arran, Islay, South Uist, Harris and Lewis) coming back on to the mainland where necessary this July and/or August. Not too worried about the availability of campsites but I have more concerns about the ferries between the islands (direct and indirect via mainland) at that time of year. I don't think I would be able to book ahead by much more than a week but we would have some flexibility. Would we find it really difficult getting a ferry at that time of year? Another potential issue is our motorhome is 7.4m long.