For us, the problem with clear weather is that it usually means colder night temperatures as well. The ideal situation is a low lying layer of stratus clouds.........keeps it in the high 40s. I would get on the leaf curl sprays now, before bud break.
Our winters are so mild, I don't think you risk much pruning grapes, but why not wait til February when it is a bit warmer out? Nothing much gained by doing it now, and if we did get a real arctic blast, you could get some die back of the buds closest to the pruning cuts. If you spur prune there will possibly be a major loss of primary fruit buds.
One decided advantage for waiting is that by Feb, you can see pretty well, which canes are damaged or diseased, while right now they may all still look pretty good. Haste makes waste.
Unless you have 20 acres of grapes, wait a bit.