Victoria is the key source here because she is hard core when it comes to racing! Thank you for all of the helpful information on weather temperature. Pleased to hear that you got a long sleeve wetsuit, Charles. This will help!
If you are sensitive to the cold, I always recommend a neoprene swim cap. Since you lose most of your heat through your head, this is a fantastic way to manage your heat/body core temperature. Here is a link to an example (you can also purchase on Amazon for faster shipping).
In addition, you should consider what to do once you come out of the water. Often the water ends up being warmer than the air. Thus athletes get chilly on the bike early on (before warming up). If you are using this race as a tune up race, don’t be afraid to dry off (quickly, of course) and even wear layers. Wear something that will bring your body core temperature up until you warm up on the bike and then you can shed if need be (long sleeve shirt, light jacket, etc). Arm warmers are another option since you can roll them up and down as needed. However they can be hard to get on after you are wet.
Another option is to simply add toe covers to your bike shoes. They won’t add any additional weight and they can help keep your toes ‘warmer.’ Depending how cold sensitive you are, you can also break open toe warmers before the race and put them in your shoes (or gloves). They will be good and warm by the time you get out of the swim and will help warm up your extremities out of the water on the bike.
By the run, you should be good and warm! 🙂 Good luck out there this weekend to everyone racing!