We were there 3 times last year, April, May, and October. We were there in April, July, and September the year before. I was able to get FP for 7DMT on all those trips except for this last October. I was able to get FP for Frozen in October.
However, sometimes I had to work hard to get them. If I couldn't make FP for 2 at the 30 day mark, I would try to make them individually and then keep playing with the times till I got an overlap. If I wasn't able to get any FP for those attractions, I would keep trying multiple times a day during the month. I got the FPs for Frozen 3 days before we left. While we were there, my D-I-L was able to get FPs to Frozen for 4 on that same day. The point being you can probably get FP for anything if you are dedicated, but there is no guarantee.
I had no problem get FP at the 30 day mark for the other attractions. BTW, there are tiers in Epcot, so you can only get a FP for one of the headliners....either Soarin, Test Track, or Frozen.