If you are able to comply with your weight limit with a full tank, no problem. I tend not to fill the tank at every aire with a service point, but reckon never to go below 1/3 of a tank if I can avoid it. On this trip, unusually, I came across two aires in succession where water supply was a problem. At the first, a free supply that had been working the evening before produced nothing but gurgles the following morning. I wanted to be on my way, so did not contact the mairie. At my next stop, the premises supposedly supplying tokens for water were either closed or out of tokens. It was third time lucky!