We are going in early May and, if I thought I could carry it, I would like the reassurance of a tent. But I know I wouldn't be able to manage.
However, I am only replying here just to warn you - in case you haven't been to this area before - that we have been on holiday in the area during the first two weeks of July for four years now and the temperature has usually been blisteringly hot - into the 40 degrees plus. However, this very hot weather is often ended suddenly by violent electric storms and a few days of rainy cooler weather.
We often went on shortish walks - it's fairly well forested so it was often possible to walk in the shade. However, I remember one year when it was so hot in the hills not far from Espalion that, when breakfasting, we had to go indoors as soon as the sun came round the corner of the mountain at 8 a..m. because we couldn't sit outside any longer (even under an umbrella). So, yes, a tent would probably be a good idea so long as you make sure you park it well out of the sun and get up early. Also if I were you - I would sleep inside if electric storms are forecast.
All the best, Windy