A Dehumidifer is hard to find around here this year. We have had rain, until late last month, most days. The Basement has leakage from the earth and mold.
We've not had any problems with the motor home in that regard but cool or cold and damp weather a dehumidifer would be welcome. Got one on order for our basement and will have one for the motor home before we head out next time.
If you are not going to check on the RV every day or two in the kind of weather we have been having e sure to run a discharge line to a drain. The included buckets will probably overfill.