I am not sure about camping. I would guess there won't be any allowed on grass in pit areas. I'd suspect they might allow self contained in parking lot. Russ Stark and crew should be putting out info shortly.
The event in Vegas being held in October is in fact in part due to extreme Temps in summer months. For many years, the nats were scheduled during summer months to allow for kids to be out of school and families to use vacation time. School schedules have changed and in fact many are now even on year round schedules. Families are taking vacations during various times of the year. Russ typically holds the premiere gas boating event of the year in Vegas during the last couple weekends of October. Instead of their being a World Cup, it will be the 2017 Nats.
I suspect that the 2018 Nats will likely also take place later in the year and possibly even in September.