I am going to assume that the Indoor storage facility you are using is not air conditioned. One thing you probably do not have to do is cover the RV during storage unless you want to keep it from getting dusty.
Another step I would urge you to take since there is no electricity is to disconnect and store your house batteries and chassis batteries. Before you disconnect the batteries you should check with the storage facility to make sure that they will allow you to do that.
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