said by tschmidt:
Will it work - yes. Is it optimal - no.
Static IPs are much better for commercial use that require an inbound connection. How well Dynamic-DNS will work hinges on how often the IP address changes and how quickly DNS is updated. During the update process your employees will not be able to connect and existing connections will be dropped.
Very true, Tom. Static is better. However, an IP change and subsequent dyn update won't happen during an active connection. It only happens when you've already lost the connection and therefore no one is connecting anyway.
I've been running for some years now a multi location VPN with various ISP (including fairpoint), with a mix of technologies and more than not are dyn (some there was no other option). The majority of the dyns, even when the connection was dropped tend to renew the same IP anyway after drop. True there is a time delay between when the router is back up and updating the dyn account, but it's never been more than a couple minutes. Losing the connection including an IP change happens seldom for us, although it happens. Some sites more than others; some never. We are in the NE too.
IMHO depends how stable OPs connection is to warrant an extra $75 a month for static to never have to worry about that. That's a lot. If it were me, I'd get dyn and see how it goes. If it's trouble then the ISP would have no problem upgrading their account to the more expensive static for $130. I'd even consider getting 2 connections, since the RV is a dual WAN router. That doesn't give you more protection, but more bandwidth to load balance and at $55 ea. that's $110 which is still cheaper than the static.