I normally use the park hours from the previous year. It can be a bit hit and miss, but for the most part, it is accurate. I am sure many others do that too. Unless you are specifically looking to eat very early for breakfast or very late in the evening, it should't make too much difference. Also, with EMH, only very few select restaurants stay open and most of these are usually CS (from my experience). I do see however, that you are trying to work around the EMH, so that may prove a bit more tricky.
i am sure that they will bring out the park hours in accordance with the 180 days out ADR's - otherwise everyone will be having the same problem.