There are a few ways to go about this, and Hughesnet has a pretty good history of helping customers that are in need, so costs will probably be very low, if they exist at all.
You could cancel service, however, that would require you to return the modem, and transmitter on the dish. This would also require you to pay any ETF if applicable and sign up as a new customer later on.
Your other option could be to suspend service, though suspension will only last for a few months, and you would still have to pay the lease fee and taxes if you're a lease customer.
The last option, and whether this is possible, or how much it may cost, is up in the air, depends on current Hughesnet policies, is to get a technician out, and do a pole mount and get the system operational again, this would allow work on the home to go on without impacting service.
I can't give a real solid policy answer, but im near certain that Hughes will send out a technician and do any repairs or replacements of the equipment for free, and I believe that will include the satellite dish itself. You need the dish for the system to work afterall!
But in regards to the cost of getting a pole mount, I had a mounted pole when I had DirecTV in 2011, and it was I think 75$ extra.
So I think that'd work to get you back up and running and allow you to keep service during the roof repairs! But I don't know if they'd come and put it back on the roof without a fee though, but if it they did, it likely wouldn't be too much.
I hope things go well repairing from the tornado!
I hope everyone's okay.
Update - they are sending out a technician and waiving the fee due to the circumstances. That's so fantastic and helps us out in a pretty stressful situation. Kudos to HughesNet.
We are sorry to hear that you were affected by this. I'm glad to hear our representatives were able to help you out with this issue. If you need any further assistance with this process or have any questions, please reach out again.