Month to month in Europe

Since you mention spending the summer in Europe, you need to know that many of the countries on the continent of Europe are part of the Schengen Zone, and you are limited to 90 days in that area within any rolling 180-day period. 90 days is not 3 months. Unless one of your destinations is in Ireland or the United Kingdom, you may run afoul of this restriction, so be very careful about your calendar arithmetic. Both your arrival day and your departure day count, and going over 90 days is likely to result in a fine and possibly being banned for a period of years.

If you want to spend more than 90 days in Europe, you'll need to include some time in non-Schengen countries. Go to page 2 of this link to see a map of Schengen and non-Schengen countries. All the green countries (light and dark) are part of the Schengen Zone.

Definitely be aware of the 90 day Schengen rules.

But "Summer" =/= 90 days.

Plan to stay less than 90 days total (counting arrival and departure days) and you shouldn't have to worry too much about it. Just don't miss that flight home...

I spent 11 weeks this summer in Europe, so I envy your planned trip for next year. I really don't think traveling in Europe is the same as what you are doing in the US with an RV. I am assuming you are using a car along with your RV in the US. In Europe if you stay in one place for a month, you will be limited to the distance you can drive or take a train, unless you stay in additional accommodations while touring, which is an added cost. While we speak of Europe being small because each country is generally not that large, it takes a lot of travel time daily to sight see. I would suggest you consider staying in strategic locations for no more than 7-10 days and take day trips by car or train unless you are just focusing on one area per month. The longest I stayed was 10 days in one place in Tuscany and took day trips to different cities. I could be wrong, but I don't think you will save a whole lot of money staying in a place for one month considering the costs of fuel, if driving or train fares traveling to other cities. Also, keep in mind if you wanted to visit Florence, Rome or other major cities and you are not staying there, you will commute there maybe 2-3 times to see all you want. Just a thought. Enjoy your trip.

Some accommodation in beach resorts offer discounts for a 4 week stay in winter, such as southern Portugal, where you will get 4 weeks for the price of 3, but you are unlikely to find many places that offer significant discounts in the summer as they can let their properties more or less every night.

Booking.com, Trip Advisor rentals and VRBO will have rentals. There will also be local letting agents in wherever you are looking. In most countries, for a 4 week letting, you will have to take a holiday letting, as standard residential letting that locals will take will be for a longer minimum term (e.g. this is 6 months in the UK) and they need bank references for non-holiday lettings and deposits.

Is Europe through the backdoor a good guide to finding monthly accommodations?

No not really.

Most travelers here have a hard time getting 2 weeks off, let alone a whole summer. Many people rush through barely spending a couple of nights in any major city and less in smaller ones, so the books are based mostly on hotels for short stays, with some reference to short stay apartments.

Will you be bringing your RV with you?

I saw a jeep this morning with a tow bar on the front and Georgia plates this morning. First time I have seen that here.

I see that you posted this question in the section of the Forums reserved for people to post reviews of trips that they have had in France.

Do you expect to concentrate in France?

You may get more answers if you post in the regular Q&A area for a country. If you haven't settled on a country , the non specific one is General Europe.

I agree with threadwear about the probable inadvisability of staying put for one month on what I'm guessing is a first trip to Europe. As pointed out, the transportation cost of your day-trips will be considerable. There are places in Europe where I'd happily spend a month at a time, but those are major cities with dozens of sights that would interest me without the need to drive or take an intercity train to different towns. Or I'd spend a month in one spot to do something special (take language classes, work on a book if I were a writer, etc.). I just don't know of a smaller place where I'd want to spend a month, taking a lot of day-trips, because of the cost in time and money to make all those side-trips.

Some areas of France rent apartments on a Saturday-to-Saturday weekly basis during vacation season.

I assume you use your own RV in the US, which I assume(without personal knowledge) is a cost-efficient way to travel. Be prepared for sticker shock in Europe.

Definitely research fuel prices, which I think are roughly twice as high in Europe.

The British AA (Automoblie Association) publishes lots of info about driving in different countries. It is designed for British drivers, so it highlights differences to UK law, and ignores things that are the same (like never overtake on the wrong side, never go through a red light).

Start with this webpage: https://www.theaa.com/european-breakdown-cover/driving-in-europe
it also publishes monthly surveys of fuel prices in each country, see here: https://www.theaa.com/driving-advice/driving-costs/fuel-prices

And the golden rules for driving:
Do not expect to be able to easily drive into or within cities, most cities this is not allowed.
Do not expect a hotel to have parking, always ask.
Do not expect parking to be free, it usually costs.

Many of the properties listed on Air BnB offer monthly rentals (30 days) at a reduced rate, but be careful of the cancellation policy. It may be different from the regular cancellation policy for the same property. I learned this the hard way.

Note: If you are going to be there 3 months, you might want to come and go through Paris. Longer term car rentals are best done by leasing cars through AutoEurope.com or one of the French auto manufacturers' leasing programs. They are cheaper and have better terms than renting a car week to week through one of the big car rental outfits. You can pickup and turn the cars in at other cities, but there is a transportation surcharge.
I prefer to stay in an area about a week and move to the next interesting city. ;And I try to stay outside of larger cities--taking day trips into towns during the day by train, if possible. Parking in big cities is expensive.

This, in my opinion, is the best way to get to know EU. Start with a site I have used for Heidelberg ( stayed 3 weeks in a small studio) . Try bedandbreakfast . de. You can choose English language. Become familiar w/ the legend, and look at the cities. A month in Paris? oh my...wonderful! A month in Heidelberg? or Strasbourg? or Vienna? or Florence...wow. as I recall, some places do rent cheaper by the month. I think that site also has some French places.

I don‘t think Europe Thru the Backdoor will be of much help. Each country probably has a different good resource. In Germany, each town has a website that will usually list all accommodations. In France, Gites de France is a resource.