Having looked at all the threads on The Grand Tour (many thanks - highly entertaining!) I'm thinking maybe I should revise my basic gameplan, and concentrate on basing myself in just a couple of places, then using them as bases to do a bit of exploring in the locale. So maybe a few days in Port Charlotte, with day trips out around Islay, and maybe pop over to Jura, and a few at Inverary or Rowardennan, pootling off around Loch Lomond/The Trossachs. I don't know...I just think maybe I was being a bit ambitious - all those hills & headwinds sound daunting (and that's not even bringing rain into the equation)!
I think Islay's a definite. I'm kind of wondering about whether to make the other half isles (Mull?) or inland - The Trossachs. I need to start making my mind up/some decisions soon tho', that's for sure. Thanks again to all who've replied - lots of excellent grist to the mill!