Travel by bus for those with less money and lots of patience
Now if you’re travelling for up to 8 hours a day, then buses are the cheapest option. You will find connections all over the country so easily and for the smallest price.
Plus at the international bus stands, you can hop on a bus from London for Paris and from there on to many other places. Just have a look at bus schedules, routes, and rates once you have decided your next location.
I would not suggest to have one long drive, for more than 8 hours. No matter how comfy the buses, it isn’t healthy to sit down in limited number of positions. Buses do stop but not enough to give your body the movement it needs.
Instead make a stop in a city relatively in the middle of your journey and start again after a day or so. This will not only give you the chance to see another place but give you rest.