Mrs GDRS and I did it a few years ago. From Toulouse to the Med over a week.
We did it on rigid mountain bikes – Mrs with Paniers and I towed a bobyak. we camped. We got to near Toulouse on the ‘bike bus’.
I would actually say don’t underestimate it if you have not done any cycle touring before. There are no shops between towns – camping involves leaving the canal path for extra KMs at the end of the day (unless you can find a spot to camp ‘au savage’).
Take good lights as finding shops and places to eat often involved a bit of cycling after you pitched tent etc.
Campsite in the centre of Carcauson is great (location and value). And Time your depart from Touluse for a morning. We went in the afternoon and got a bit stumped for a place to camp at dusk (truck stop next to autoroute – not ideal).
It was great fun – the cycling was relatively easy – it was not at all congested – the bit at the end near the med is the worst section (path, people and camping options near Sette and Cap d’Agde have lots of rules – and can involve nudism…….)