I think the nearest you'll get is to use Chrome and plan your rides on Strava with the Veloviewer extension for Strava installed.
The darker pink squares are ones I have already ridden through, the bluish squares are part of my max cluster, the blue line is showing the western edge of my max square. The lighter squares are ones I have yet to ride through.
The drawbacks of Strava compared to RWGPS is that if you have to go off road the Strava 'manual' routing is not so good as RWGPS 'Draw lines' function and the step by step route instructions are not as good on Strava either.
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