Thank you for your query. I am a Solicitor-Advocate in the UK and will.be assisting you with your question today.
You have two questions here.
Firstly, can your husband work from France? The sime answer is possibly. It all.depends on his contra t and where it states his place of work to be.If he is required to be in the UK and attend sites in the UK, then maybe not.
If his location is not stipulated, then maybe yes. The best thing he could do is speak with the employer and raise the question with them. He would not want go have any ambiguity and them decide to move to France only to be told he should be based in the UK.
Secondly, what I'll happen post Brexit. As any other national of an EU state coming to the UK, you will.need the relevant visas to enable you to settle in France. If you leave before 31st December, you would be ae to go to France and register before the end of the year.
I hope this answers your questions.
If you have any further questions, please do not hesitate to ask.