I got a FP for FOP for 5 at 58 days last May. I've also been able to snag day of for 3. Sorry didn't note how many are in your party but you can also try to split them up into smaller groups if needed and try to get overlapping times.
My story from May 2018, we rope dropped AK for a 9am opening (only 3 were getting on), we got there at 7:30 and CM's let us in around 8:15-8:30 (sorry don't remember exact times but it was before scheduled opening) and my DH, DS, DD got on in about 20 minutes. They also had a bit of pixie dust as the CM was calling for a party of 3 and they got to skip the line but at most it would have been another 20 minutes. Total time from arrival to off was 90 minutes then they rode Navi with me and DS2 multiple times. I look at it this way, if you are ok with waiting 90-120 minutes in a line, why not let 60-90 of those be "non-operating time". You aren't wasting valuable park time by getting there way before opening vs getting there are 9 and not getting on until 11. It also allows you to enjoy the rest of the park while all of the non-crazy rope drop people are waiting for FOP. In our RD May 2017, DH, DS, DD did FOP at 8:30, DS2 and I did Navi about 3 times, then all 5 of us did Navi 2 more times, we hit EE 4 times, then went to our Safari FP at 9:45, and then Tusker House ADR at 10:30. If we hadn't RD, we'd most likely still be in line at 10:30. There are few experiences where my kids are ok with being up before the sun and Disney (both WDW and DLR) is one.