If you have 2 OBi1xx's registered to one GV account you can make outbound calls from either.
The last OBi to register to GV will receive inbound calls, so you could reboot the OBi at your current location to receive calls.
You could setup each OBi to ring the phone port on both OBi's, so you don't have to do the reboot.
Change Voice Services -> SPx Service -> X_InboundCallRoute:
From: ph
To: {ph,pp(123456789)}
SPx is the SP where GV is defined.
123456789 is the OBi number of the other OBi.
The above uses the OBitalk network to route the call to the other OBi.
Now it doesn't matter which OBi receives the call, both will ring.
The OBi2xx has an option where both OBi's will receive the inbound call.