Hi JulieL,
No Problem! Layers is the thing here, as it can get a bit chilly in the evenings. I took tops and cardies, and for the most part wore trousers for comfort. This is technically quite a casual holiday, so I only really took 2 "dressy" type clothes with me as most of the time eating out at night was casual too. I also took a light, but warm, jacket with me - and a brolly, just in case (only needed it once in the whole time I was there!)
So, simply take clothes that you know you feel comfy in, and layers that you can add for the evenings. Wherever you go on this trip, there are plenty of restaurants close by, so if it is wet, you won't have far to go. And on the couple of nights where the meals were organized by Gary, our tour bus took us and brought us back.
Hope this is of use to you, and enjoy!
Anne