Chamonix to Nice

Debating which route to take. Faster 5 hour route through Italy with hefty tunnel toll vs scenic drive along Route Napoleon which takes 8 hours. Husband will be driving and narrow winding roads aren't a concern, and 8 hours isn't a big deal in itself. We drive 15 hours at a stretch to go watch our horses race. (Yup, we're crazy) Wondering if it would just be a grind watching the road and not enjoying the scenery in a little stick shift rental. We could break up the scenic drive if there is anywhere worth staying overnight. Is the Route Napoleon scenery worth the time and effort? Looking for your experiences and advice.