Be very careful with a "converter". Most of the cheap ones are sinmply a diode which cuts off half the wave of the ac. This gets anything with an inductive load (motors, transformers in device chargers) very hot and will burn them up quite quickly.
You could go with a heavy-duty transformer with 240V in, 115 out at up to maybe 4 KW. I don't think 115V/50Hz would actually damage anything. but motors would run at 5/6ths their normal speed.
Maybe a second sinewave inverter and more battery capacity would get you 4KW, but you'd have to divide up the 115V circuitry to run on one inverter or the other.
Also, watch out for power in some of the rural areas in France. They used to be 240V DC. I doubt there are many of those small systems left, but you can't be too careful.
Your US TVs won't work over there either, since France has a SECAM system and a lot of other countries are on PAL systems. Only the areas near US Forces bases will have NTSC.
Frank and Eileen
No longer RVers or FR owners