Does anyone have advice on most affordable way to rent/borrow an RV? :)

VERY random but I know some folks here have done multi-day runs with groups where people are sleeping in vans/ RVs (Hood to Coast, TSP, etc.). I was wondering if anyone had suggested resources or connections!! Any bit of information or advice is so so valuable and appreciated. For context, I am planning a cross country bike ride in June 2024! My support crew (aka my friends/fam) and I will be driving + sleeping in the van. Love you all!