Well, if you roast it this Saturday (9/10), wait a week and then brew (9/17), ferment for 3 weeks (10/8), and wait the suggested 3 weeks (10/29), you still have a buffer of 2 days before 10/31. I am impatient too, but my wife will just have to wait.
I am doing this recipe soon too. I ordered the sorghum online and I plan on roasting it tonight and brewing next Friday. I am kegging it and I hope it will be ready in 6 weeks or so. This will be my 2nd time brewing (by myself) and the 1st partial grain batch. Should be interesting.