I'm not one for big daily mileages, prefer small chunks.
My recent longish rides have included two Raids Pyrenean. The the first was West to East touring version, 790 km in under 10 days over 28 cols we'd good weather until the last couple of days when the rain was torrential. It was about 50 miles per day for 10 days.
The 2nd Raid was the 'randonneur' version of 720km over 18 cols to be completed in 100 hours. We did this East to West with Marmot Tours* and their schedule was:
Day 1: Hendaye to Lurbe St Christau (160km with 2200m of ascent)
Day 2: Lurbe St Christau to Aste (140km with 3530m ascent)
Day 3: Aste to Massat (170km with 3110m ascent)
Day 4: Massat to Prades (145km with 3400m ascent)
Day 5: Prades to Cerbere (98km with 620m ascent)
It rained every single day! On the ascent of the Col du Tourmalet the rain turned to sleet then snow. The descent was epic. Unfortunately due to the cold, at first it was necessary to pedal down to prevent shivering from shaking the bike. Having mudguards the phenomenal road spray was not a problem to me (other than the fact the road looked just like a river) although most without started to walk and were picked up by our tour guides' van (it was legal to get a lift on the descent). On last day the sun shone and the wind was on our backs for a super ride along the beautiful coast road to Cerbere. On our arrival the local hostelry did us proud with food and drink plus a local band! Then it rained again.
*excellent outfit