If you cross Hope Point to Cap Gris Nez, you will be across in somewhere around 15-25 mins, depending on your aircraft and wind. If you climb to the max allowed as vanilla PPL, VFR, you are pretty much within gliding range of land.
For many of of us whose aeroplanes cannot carry much, the risk is deemed acceptable, if everything else is on our side (preparation, preparation, preparation). I write as one whose aversion to water is extreme, although I work on the same bit mentioned above. I joke that if the worst happens, I ought to be able ditch upwind of any ferry and know at least someone on board.
The joy of flying in France (and beyond) is worth it.
Jan, we'd be happy to see you over here and Headcorn is a most helpful and friendly place to start. FleetFlyer is right.