You should not worry about your speed, because there will be times that you may have to go slower or walk in the towns. Like some people said speed is not important because if you can get behind others that go fast you may be able to go fast to, following them. At the same time there will be so many people or cyclist that will slow you down.
I signed up as a solo rider but would love to join a team, a group or others from Florida. I am not a partier but may have 4-6 drinks a year. I am for the enjoyment of the ride. I already signed with Out of Staters to take me from Keokut to Council Bluffs and to carry my stuff. I will be camping with them. Thanks