So is the issue speed? If you can't use 3G card, then you maybe re going to have to find a trusted "modem", not just someone's network.
We have a major healthcare provider as one our tenants. The privacy issue protocols are very closer to DOD than corporate levels.
If it weren't for the speed issues, you might search for a small professional office that you could connect directly into their router and their service. I would suspect that bigger organizations just wouldn't want to compromise their own privacy issues.
I would call bed and breakfast places -- try the I've got a problem and I need your help.