To fly VFR you have to have the ground in sight.
No. Below 140kts, if you have the ground in sight, you are VFR, but you can be at FL75 with OVC with tops at 6000' and be VFR.
In the former case, if the visibility is 250m (a reasonable bet for R350) then you could climb to 750' and still be in sight of the surface. I am talking about 150' of shallow fog.
Alan, if I had to go back with an engine fire you would look after me on a Mayday squawk, IFR or VFR wouldn't you? Pretty please?