Connecting users from regonal offices

Hello everyone,
Well the question is that in our WAN we have some remote offices, for example, Calgary which connects to Toronto site via routers and they have assigned static IPs. However, sometimes we have our local users traveling to those offices and need to connect to the network, but there is no DHCP server available in the remote offices. What would be the best way to get them connected while they are there other than using dial-up?