Hi Michael, rose-tinted glasses? I don't think so, England is lovely, always has been :-) I can understand your wife a little. Sorry no I don't know how you can achieve it but I just Googled the subject and there are loads of websites dedicated to it.
The house swap is a good idea to get to know the area.
I returned to the UK and had a very poor experience, and it took two years to sell the place so that I could escape.
The house where I lived had windows high up, overlooking a pavement, and people enjoyed banging on these at night, and shinning up to peer in. They also enjoyed throwing rubbish in the garden. The lovely quaint English village was hell on earth.
Sorry just realised that this is for vactioning...but by posting on this site you may find someone who would be interested in doing this for a longer period....
You could try picking an area to return to and then advertising/ sending a flyer to companies in that area who may have a need for accomodation in that part of France. Do any companies in your area of the Lot have branches/links with places in the UK ?
There is another way which may or may not suit your financial circumstances and depends if you are retired or work at home. If you do manage to sell your house in the Lot and you can afford to buy a house in your chosen part of the U.K you could think about sacrificing something on your house in the UK and buying a very cheap house in France so that you can live in France in the summer for several months. I bought a detached house in Haute Vienne 5 years ago which was just about habitable (initially we looked on it as a stone tent) it cost me around £40000 all in and it costs me about £100 per month to run it for taxes, insurance and utilities. We enjoy staying in France for long periods working on the house and have gradually improved it. I would live in France permanently but my partner prefers to be based in England so this is ideal for us. I don't know if there are similar properties in the Lot that you could pick up cheaply. Avoid properties with gardens or land that would be expensive to maintain and look for a good roof. Our fosse was judged non conformant at purchase but so far it works fine and nobody has raised the topic since the purchase. Also if this might work for you think about your choice of property in the UK as one you can either rent out as a holiday let when you are in France or is a good lock up and leave property. By the way although I prefer France there are many, many good things about England and we live in a stunning and underpopulated part of Shropshire that is very like rural France in many ways.
My friend put her apartment up on airbnb.com and manage to find a renter that will be staying for 4.5 months. The apartment is in L.A. and the other party is from Aix en Provence. Both parties happen to be French, (merely coencidence). Why not check it out? There must be another site just for house swapping though, like in the movie 'The Holiday', or was it just 'Holiday'? I think it's a great idea and that way you will look very carefully, both of you, before you leap so to speak.
My husband wants to move further south because its warmer and I want to move to Bretagne because the summer heat in Poitou Charente is too much for me. I feel your pain. But we both agree that the uk has been ruined by decades of greedy leaches siphoning away our wealth to the Caymens. France has more trees more space and travelling for work here is socially acceptable and economically viable. We also have much better protection from unscrupulous employers. Besides the English weather threw a tree at our van last month. We are not happy there.
I find it very ironic (above) that someone who is an economic migrant in France is upset by the amount of foreigners in the uk.
I think trying out the UK before burning your French bridges is a brilliant idea. I had to spend three weeks alone there whilst husband held the fort here, the longest length of time I'd been in England since we moved to France ten years ago. I was staying in a small, market town in Yorkshire, a town I've known all my life and what struck me like a poke in the eye was that nobody apeared to have any respect for anything or anybody. There's an etiquette to living in France and where we live, people are still outraged by bad behaviour, which makes for a fairly civilised lifestyle. My husband sometimes hankers to return to England, but like you, I feel that we'd be giving up the substance for a shadow. I'll certainly insist on trying it out for a year before even contemplating packing up our French life. I too think we'd be making a big mistake.