The last time I did a 10 day ride, I had about a half dozen spare tires with me... and used them all.
But, that was a different era when I was still riding on sewups.
The older I get, the more self-sufficient I get.
While I might expect to acquire food and water along the way, I would not count on local bike shops being where I want them, or being open when I need them, or even carrying the spare parts that I need. As far as I can remember, I have never had a bike shop do any work on my bike, although I may have bought or bummed some tools for emergency repairs. I did manage to break my bike rack on my mega-meter trip in Italy, and found someone to weld it back together while on the road, but it wasn't a bike shop.
I did a couple of 100+ mile rides this year, and may try some longer rides next year, and will carefully consider the tools I need.
My cargo bike picked up some odd rear-end clicking as I was heading towards Mom's house before Christmas. I would have fixed it while I was there, but unfortunately she no longer has any bike-specific tools, so while she had 15 and 17mm wrenches, she lacked the cone wrenches and cluster tools. Another reason to carry a few more tools and spares with me. Ok, so I'll probably be a travelling bike shop for my next multi-day ride.