Hiya BevToo many unknowns in your situation to be certain.
What sort of partner? (Spouse, recognized civil partner, other partner?) What sort of visa will you be in France on? What sort of assistance are you looking for? (Housing? Child benefit? Health care?) You say you'll be the only bread winner - do you have a job? What level of income are you looking at? Will you be paying cotisations into the French system? Do you have any transferable benefits or rights to benefits from the UK system?
We're not yet in Paris, but I was researching options. Our situation is this: civil partnered, he will be a student and I will be getting a carte de séjour vie privée based on his EU citizenship. We would be looking for housing benefit only because we dont' have children and we'd be able to benefit from the European Health Insurance Card (I've already gotten mine, his is being processed). I am to be looking to find employment as a chef, so it would be full-time employment and I expect to pay cotisations. I've been paying into the UK's National Insurance as has he - we both work full-time here. We will have a fairly substantial savings when we arrive, but we'd rather not have to live solely on that. I realise it may take some time for me to find a job, so our savings may have to support us for a few months. So if there's help available once I do find something, I'd like to avail of it!