That is pretty good.
I wonder if there is a simple SV program which runs the SRTM imagery under Windows?
Actually there is one - FSX 
But it's complicated (or maybe impossible) to configure it so it just starts up by itself, in the correct mode.
Same goes for X-Plane. I've emailed X-Plane to ask if such an autostart config is possible.
Then, if you have an iPad, install e.g. AirNav Pro. It has synthetic vision
Cool! Wasn't aware it could do this. Will give it a try!
To answer the initial question, I wouldn't fly on top knowing that the cloud base touches the ground. It seems to me that even if you know very well the area, "ditching" into this layer of clouds hoping not to hit anything before getting in a valley under the clouds is a hell of a bet. I would rather fly around the clouds or around the mountains. To go to Cannes for exemple, I would rather fly along the Rhone valley and then turn East than fly over the Alps with so many clouds. Or maybe would consider flying under the clouds, depending on the clouds height and the route. In most valleys, the sides of the valley are not parallel to the ridge. There are a lot of lower mountains, mountains shoulders and so on which can really twist the shape of the valley. I have no screen in my airplane (no glass cockpit, no ipad) and might think differently if I had. In my opinion that's a scenario where a twin is really worth the money it costs.
