M105,
Since you are the system admin in both homes you could setup your router with port forwarding to each OBI. If you can get to the OBi web page of the unit over the internet, you should be able to reboot it that way. If you have not set this up prior, you may not be able to this at this time. If there is a computer running in the other home you could remote into it and reboot the OBi by going through local web page. This also needs to be setup.
Finally, if there is someone in the house you can ask them to press ***81 to reboot from the attached phone.