For visiting places I always look for free parking, however for Paris found them only outside the city. To begin it’s worth checking out if it is aloud in France (or local) parking camper vans for several days somewhere along the road. In case this is okay:
At the northside of Paris you can park for free close to the railway station in Goussainville (west of CDG) along Avenue Jacques Anquetil and Avenue Marcel Cerdan.
In Versailles in Allee des Matelots, a sidestreet of the D10 , opposite the southern entrance (traffic lights) of the huge park of Château de Versailles. The D10 runs along the southside of the estate west to freeway N12. From there it’s a serious walk to one of the two railway stations in Versailles or you can take a bus or a taxi.
More east from the D10 you can take the D91 direction (south) Rambouillet and crossing the bridge over the railtrack. Free parking at both sides of the road. Or turn left directly behind the bridge (if coming from Versailles) to Avenue du Maréchal Juin, free parking along the road.
Heard that there is free parking in Bois de Boulogne too but didn’t look there risking loosing to much time if there was no place left. But worth checking out, maybe your hotel can be of help.
These places are good for anyway parking during the day. Have no idea how safe it wil be for 5 days, that’s up to you to consider. Commuters use ofcourse these free parkings, so most of the time ocupied during the day, but Allee des Matelots in Versailles was two times the easiest finding a free spot around noon.
