Hi, not sure which route you are taking to Brieve or how far you want to go in a day. A few ideas, though.
Doue la Fontaine has a goob municipal site easily found from the bypass. The is a pool adjacent and a big supermarket no more than a mile away. Doue is the ' City of the rose' and has an extensive garden / park accordingly.
Just to north of Poitiers at St Georges is the Futuriste site again easy to find. This site is a favourite overnight for many Dutch and Brits throughout the year and is generally well run.
Just south of Brieve in Payrac there is a medium sized site Panoramique and a small CL farm site in a village about two miles north. Sorry can't remember name, but it's in the CC France book under Payrac. In nearby Souillac is a splndid museum of automatons next to the fine Roman church, also supermarket.
As for negotiating Tours, as for any city that has a motorway passing near, use the motorway for two or three junctions. You will find that many of the sections near cities are toll free or if not the fee will be low and well worth it to avoid city traffic, particularly if you are 'convoy' with another outfit.
As you probably know fuel is much cheaper at supermarkets than main roads and particularly motorways. You can often avoid narrow access at supermarkets by going to the 24/24 pumps which may be card only, but easy to use and exit from.