I used to do some longish trail runs accompanied by a border collie mix, and sometimes a black lab too. I'd say the border collie mix was a little better suited to it. They were both able to more than keep up with no problem as long as we crossed plenty of streams where they could get water. I never took them out in extreme heat. I would estimate that they covered about 50% more distance than me with all their little side trips chasing various furry things. I once took them on a trail run of about 30 miles (for me), and the extra time/distance didn't seem to faze them.
It was hard to tell what pace they could have handled if they were sufficiently motivated. I'm pretty sure they must have covered 40+ rugged, hilly miles in ~4hrs when I took them on my 30 miler. I would usually pack a couple of treats for them to eat en route, but I didn't get the impression that they particularly needed to refuel.
I had an ultrarunner friend who also had a border collie who ran with him on his long runs. He said his dog was able to cover 50 miles with him no problem, even demanding to play fetch with a frisbee as soon as they got home afterwards.