I just use little magic glove type thingies, but I have a pair of Inov8 mittens on string round my wrists so I can pop them on and off when the wind comes in to keep them warm. If gloves get wet they help warm the water up so your hands are at least warmer. Also tucked my base layer sleeves into the gloves to keep wrists warm which helps a bit.
I'd also say sack off 2-race-Saturdays and long race Sundays, but it's up to you if you want to weekend warrior!
Good plan re the mittens, thanks will try that.
If I had a realistic chance of winning like you do Nic, my race strategy would be a bit different. Whilst I might like to believe that racing on Saturday made me an hour slower, I'm not sure that that is in fact the case!