I am a week or so behind you. Yesterday's low was 21, this AM 34. Looks like a cool next 5-7 days with several fronts pushing through so hopefully they will all stay buttoned up for a week or two more. Be nice to hit May without any real push.
I have 3 varieties and they all seem to break bud a little different and ripen at different times. Are they swelling/pushing at all? Scrape the bark and look for green wood. Brown is bad. I would think by now you should be seeing some swelling. I have lost a vine or two each year for no reason that I can tell except that these were all vines I ordered by mistake on grafted root stock. One by one they have been dying off after growing well for the first 2-3 years.