Although Paimpont is awash with tourists during July and August, Mitzi and I make our tour of the lake before they've had their croissants. This 'light window' overlooking the lake was an oasis in the desert. Quiet, serene, soft shades, varied textures...and not a soul in sight.
It is possible to enjoy lake views in solitude even in high summer at L'Étang du Pont Dom Jean... but as that entails a 30 minute walk into the heart of the forest, I'd prefer that you keep getting up early ;-))