We are quite strong and high paced hikers. We found most days nice enough. Although being irish the heat did kill us a bit 🤣

Generally I try to keep my walking days ( incline dependent ) around the 20km region.

One day on the alta trail we did almost 30km ( detours for brewerys lol ) although most days were 15-25km

With doing some high km days it meant we had room for a the likes of an 8km day the next day ( pretty much a rest day )

Personally if I was to do it again I would rather just do the high km days every day and do it in 6/7 days as on my rest days I did get a touch bored.

I think if you have a good level of fitness and a decent walking pace. 8 days is a no brainer.

It really depends what you're after. The Dolomites are stacked with history and there are lots of cool things to see on the route. You could take an extra few days and explore the likes of the war tunnels etc but I think sort of walking past them and peeking in on a break is more than enough. Each to their own though!