Is it possible to use the pay-as-you-go mifi as a local-only(IE, no internet connection), ad-hoc wireless router when you don't have an active data plan?

I want to be able to create a wireless network between my iPad and wireless camera card. I don't always need internet access, but the two devices would still need to be able to get IP addresses from the mifi via DHPC, and still be able to talk through it.

Is this possible, or is the device completely disabled when there is no active service plan enabled on it?