A75 across the massif Central

Qashqai66

A question plese for those of you who know central France better than I do.  After several years of travelling almost exclusively to SW France we are considering driving down the A75 from Clermont-Ferrand to Millau.  The last time I did that specific journey
was with driving with a university friend in a Mini in 1964, i.e long before autoroutes.  I have read somewhere that the stretch of the A75 is not suitable for towing because of its height and gradients.  We tow with a Nissan Qashqai 4X4 auto and our caravan
is 74% kerb weight.  Generally speaking we ascend the steepest UK gradients without having to reduce speed, subject to raod conditions of course.  Can anyone tell me if this stretch of the A75 is likely to be problematic?