Can I create ad-hoc connection over VPN?

I need to connect two machines, one of which is a tiny Linux computer capable only of ad-hoc Wi-Fi connections. The problem is, the two machines are at two remote geographic locations, so direct ad-hoc Wi-Fi is not an option. The connection has to go over the internet.

The question is: can I put a VPN-capable router next to the ad-hoc-only machine, then another router with the other computer, and then create a VPN tunnel over the internet? My hope is that the VPN would function like a repeater and let the two machines connect via a "virtual" ad-hoc connection.