I do not know if it is possible to set a satnav to give a route avoiding the congestion zone. However, the boundary of the zone is Vauxhall Bridge Road, A202, then the A302, A4202 (Park Lane)and A5 (Edgware Road). Your destination is just off the A5. I believe that it is possible to set up a satnav route with several waypoints. In any case it would appear that the boundary of the congestion zone is likely to be part of the optimum route offered anyway. Otherwise, make a careful list of all the roads and turnings or use each of your satnav apps to cover part of the route. I hope this is useful.
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