I just logged on to post about that event postponement. You beat me to it!
For practice, if you can be or will be in KS the weekend before the Solo Nationals competition, look around for practice events. There should be several to choose from. Everything from the Pro Solo finals to Kansas Region's typical practice event ON Forbes Field, to a possible Salina Region event on good concrete, or even a Wichita Region event (though it wouldn't likely be on concrete) all within 90 minutes of Topeka. Plenty of opportunity if you look for it.
I can hook you up with some locals if you need help. I know lots of Wichita Region people.