Currently living in the US, I would like to travel to France for a maximum of 6 months and continue working remotely (French citizen with US L1 VISA).
How should I declare taxes? Should I declare taxes only to US?
According to (my reading of) the tax treaty between France and the US, you would only be taxed in the US provided:
As a general rule in France, you cannot be fined by the tax office if you did not owe any taxes so not being taxable effectively means you don't have to file a return (unless you have some property in France or French-sourced income beside your salary).