So I set off from Morningside at about 0645 this morning. Morningside Drive was sparkling in my headlight. I stayed off bike paths on the way out of Edinburgh, and the roads were fine apart from a sketchy moment on the Low Road round Arthur's Seat. There was little traffic. A tailwind eased the ride east along the coast. The live traffic lanes were all fine, although bike lanes and shared use footways were all frosted and unusable ( no surprise there). The back wheel got a bit lively a couple of times near Whitekirk, but actually the biggest problem was my fear of encountering ice (which meant I couldn't let the bike freewheel unrestrained on the downhills) rather than ice itself.
The steep down and up to Pease Bay was icy in places, and I nearly came a cropper as I dismounted at the ford.
The worst bit of the whole ride was the climb to COLDingham, which had large patches of frozen field run off on it. The road wasn't busy, though, so it wasn't a massive problem.
The return was windy. I ground out the miles and pedalled down the hills. It was definitely a bit nippy too, but I was quite comfortable. All credit to the Decathlon Aerofit baselayer: it has a windproof panel on the front, and in combination with an Aerofit warm jersey it's toasty warm. I had an extra vest on top of it today, and a gilet some of the time too. Double gloves, neoprene overshoes, a buff and a fleece hat kept the extremities warm.
Thanks for all the advice. Glad to be able to keep up the habit of a century ride every month, and that looked at risk last night.