Thanks all - midges were present and correct. The biggest problem is they can leave smudge marks on a shot. A technique I teach in the field is to set the timer to 10sec, fire it and walk alway from the camera so the midges follow you rather than linger around the camera/filters - leaves a smudge free shot without fail.
Midges are annoying but if they are around it means 1. Its not cold 2. It's still.
I find shooting in the cold even more annoying because I hate being cold and tripod legs freezing up, misting up cameras/lenses is a bigger drag and I like the still weather for reflections and non moving grasses.
Compared to a trip to Australia (killer snakes), Florida (killer Aligators), Africa (killer jihadists, kidnappers, killer lions, tigers and diseases) and Paris etc (killer jihadists) midges are pretty tame beasts. I wouldn't give a moments thought to going out when there are midges other than the self timer trick and to wear long sleeves and trousers.
On the whole these were an utter delight to take and imho a summers morning or evening out in a place like this is the definition of heaven.