In 2005 my husband got a concussion on a ski trip to Taos. We were young healthy idiots and didn't use helmets back then. We figured we didn't need them since we didn't do any tree skiing. My husband is a good skier and this happened on a green trail. He was trying to avoid a group of kids and got tangled in the rope at the edge of the trail. To this day he doesn't remember any of it. Anyway, we were fortunate to be in the U.S. because our medical insurance covered most of the expense. Also, we didn't have to change our flight back home as he was able to fly as scheduled. I remember thinking "What if this had happened in another country? We didn't buy travel insurance." Ever since then we have never skied without helmets and we have never gone anywhere without travel insurance.You should look at one of the recent posts on cruise and health insurance. A "healthy retired" couple paid for a cruise and 3 days prior the husband had his first kidney stone-trip canceled. No travel ins, they wondered why they could not get a refund. They were asking for insurance benefits without purchasing the insurance.
Travel insurance would cover this, as well as a broken leg or MVA prior to the trip. It also would cover illness/injury on the trip as well as repatriation (if that benefit was included). No traveler is "healthy" enough to safely travel outside the US without insurance. When I was 21 I went to London with a group; one member looked left and stepped into the path of a car coming from the right. He was REALLY REALLY healthy until he wasn't. Luckily for him, England has NHS, otherwise he would have been charged many $$$ which he did not have. As you know from your background, cr*p happens to healthy, careful people.
I spent 40+ years in Emergency Departments so I have seen it all. I recently saw a young widower traveling to ski with his 3 young kids. He fractured his femur; kids alone, can't drive, no family nearby. It was much more challenging to rearrange care for the kids than fix a simple femur fracture. Things happen.