Generally wishes is an hour after the first MSEP from what I've seen. We don't watch the MSEP so don't pay too much attention to its times, but it's enough time to make it to wishes FP. If you really want an up front spot for wishes though, I'd go to the wishes FP spot instead though. By the time you watch MSEP and then get to the Wishes FP, most of the front will more than likely be taken up. If you don't mind having a little more room in the back, then I wouldn't worry.
However, while not the best view. You could get to the Wishes FP early and stand along the side fence and watch the MSEP from there. You won't be able to see all the way to ground level, but you'll be able to see a lot. From the Wishes FP, being the sidewalk there and the CMs keep part of it empty for flow of crowds, you'll only have a couple heads of people standing in between you and the floats. You won't have a clear shot more than likely, but if you worry about getting a good spot for Wishes FP and want to show up there early, it is an option