I’d originally thought about only using a point and shoot / iPhone for a different take on the event, but succumbed to the DSLR late in the day. I only took my 70-200mm and, for post race parc ferme shots, 24-120mm zooms, but next year (there will be a next year) I will take the 200-500mm zoom as well, especially if I can find a lens elf to carry it for me !
For the night shots, I used a monopod even with the 70-200mm zoom. Bear in mind you will be walking, or possibly taking a shuttle, from your car park / camping location. I walked around 25kms over the two days this year.