La Rochelle, Aunis, Saintonge, Poitou are definitely NOT within the Occitan speaking area.
I'm from Auvergne, one of the northermost Occitan speaking areas. Not exactly south
west France, but southern half for sure. I didn't do Geno 2.0. But on Eurogenes K36, I get 22.18 Iberian, 27.28 Italian, 4.99 Basque, and 3.73 West Med, the rest being more northern (mostly British Isles, some Fennoscandian and East Euro). With DNA Land : South Central Euro (ie basically, northern Italy) 28% Southwestern 21% (Iberia 19 + Sardinia 2). Gencove : Northern Italy 26% Southwestern 17%. I guess these figures will increase the further south-west you get (Basque Country excepted).
You might be interested by this little programme someone suggested in another thread :
http://gen3553.pagesperso-orange.fr/ADN/similitude.htm You do the GEDmatch Eurogenes K36 first, then you type your results, and you get a ratio of proximity with the rest of Europe, and other places around the world. On that programme, my son-in-law, born on the Minho/Galicia border, gets his highest proximity score in... Auvergne. Yes, there seems to be a fair share of DNA that's common to Iberia and SW France.