A few things to think about. Being a registered rider or non rider gives you some insurance out on the road. If you need emergency service from one of the RAGBRAI ambulances. The cost is covered by the registration. It also gives you access to sag service if needed. But a child under 6 or any child that needs a child safety seat. Will not be allowed on a sag wagon. This is due to Iowa child safety seat laws and liability issues. You will have to provide your own sag service for the child. Please consider Iowa weather. When the heat indexes hit near triple digits. Your child will be a few inches off of 160 degree plus pavement in a trailer. A child can dehydrate or get heat exhaustion easily. I would only consider the shorter days to take the child out on the road. If you are camping. Please be aware temps could plummet to low 40’s at night. Many families have done what your planning. They have a safe and good time with there kid/kids. The key to it is planning ahead and having backup plans.