Won't know until the cybertruck comes out. Different battery pack than the rivian. 4680 cell will give a different range compared to Rivian. The rivian is also heavier then the cybertruck, from the reveal in 2019.
There's also new technology for RVs, to be more efficient like having their own...
1..Fold out solar panels to cover the entire truck like an awning, perfect for camping
2.. fold down rear seats for bed extension
3.. SpaceX package, which would include pressurized cabin. Air pressure boosters.