Disney World Discussion

Can anyone provide perspective on how difficult it is to secure a place in the Keys to the Kingdom tour on a specific day at MK? My husband and I plan to have just one park day on a trip in March and we would love to go on the tour. We are staying on property and know all about the 60 day in advance thing and we will be online at 5:45 a.m. trying to get a reservation. But, since it will be during a busy time, we are wondering what our chances will be since some folks will be staying much longer and will have access to our preferred date before we do. Also, there are only a few time slots so we assume the availability is very limited. Thanks!