We have sort of looked into rv travel overseas and determined that we would probably rent or buy a vehicle there rather than try and ship our camper. For a two year trip we would either store or sell our current camper here in the US.
Converting your truck to electric is a huge and expensive experiment and would limit you to European charging voltages and charging locations. You will be essentially reinventing the wheel for solar RV travel anywhere. No amount of roof solar would build out a system that is even partially functional and the generator and fuel needed to move the rig would also be extreme, expensive and wasteful.