Thanks to everyone who helped especially @scotroutes.
We had a week up there in early Sept and it was fab (despite the seemingly 40mph winds).
Lewis
The site at Shawbost was good and the owners really nice and helpful. Callanish stones were very moody in the torrential rain but still pretty busy.
Uig was lovely and the food at Uig Sands was really nice!! You can can sleep outside in your campervan if you pre-book with them. The iron age buildings and beach at Bostadh on Great Berenera were amazing. Interesting tidal bell sculpture there too.
Harris
Luskentyre was nice but it was so busy, I was really shocked. The road to Huisinish was a bit scary in awful weather but worth it with the walk over to Traigh Mheilein. The Harris Trust motorhome pitches are in such an amazing location. The drive out of there in nice weather is pretty straight forward though.
The Golden Road was simply stunning and we managed to do it on a sunny day with light winds (15mph).
With the winds being so string most of the time we didn’t get to walk up any big hills whilst there but they’ll still be there next time..
The campsites we stayed on at Shawbost and Seilibost didn’t have open toilet/shower/pot washing facilities but if you’re self-contained you can get by. From what we saw, the majority of people were camping responsibly but there are always people who know better and do whatever they want.