RE: Chef Mickey's ...I've heard that if you go right when they open, sometimes you are able to get in without a PS.
We went to WDW last year the same time you are going. I recently pulled out my itinerary and saw that we only got PSs for Character meals and special events for the kids. Otherwise, we winged it. Remember, you can make a PS while you are down there when you are a bit more aware of what your touring plan will actually be.
Come to think of it, we were able to get in to LTT in the MK for dinner on a Saturday in mid-August last year. We went to guest services earlier in the day to make the PS, and we did the same with a CP breakfast, making the PS the night before. It can be done!
HTH!