Hi, just a small question here, and hopefully it's one people can help me with?

So, I'm a writer in my spare time, and I was wondering - basically, what is a realistic distance for a horse not bred or trained for distance running (think, like, a farm horse who is used to drawing ploughs and potentially wagons, etc) to be able to run, along with a rider? The 'scene' is essentially time sensitive for the characters, and while these details are usually glossed over in writing (or grossly overexaggerated), I would hope to be more realistic with my writing 😅

The best estimate I have found is that a racehorse can run for two miles when pushing hard, before fatigue sets in, and five if the horse is going at a reasonable pace. But I don't know if this can also apply to horses that are not trained for speed. Ergo, here I am. Any help is much appreciated!