D&D 5E (2014) Miles per day on horseback: how many?

[Ferrousbones]

This question (How far can you travel per day by horseback, RAW) (as well as travel by magical means) led me to a deep look into 5e's rules on Travel, which led to looking at Resting again, too, and it is a little surprising.

RAW, the Forced March rule doesn't apply to all Travel, as evident by being able to travel 24-hrs/day by sufficiently crewed ship. If it did, everyone traveling by ship would quickly die of exhaustion.

Further, ironically, while 1-hour of walking is strenuous enough to interrupt a Long Rest, that isn't all Travel (again, as evident by ship travel), so Travel by means other than one's own movement can be longer than 8-hours without exhaustion.

Last, the context of "fresh" in the gallop rule would be well-rested/not-risking-exhaustion, typically by way of a mount that hasn't Traveled via its own movement.

So, accounting for those rules and context, I think the max distances for non-magical horses are:

1. 30-miles/day using the standard pace table (all non-magical non-flying travel is limited to the paces in the table)
2. 36-miles/day including 1-hour of gallop (to fit the multiple of 6 format)
3. 60-miles/day by swapping to fresh horses after 8 hours, assuming a race that need 8-hours to Long Rest
4. 78-miles/day by swapping to fresh horses after 8 and 16 hours, assuming Elves (due to 4-hour Long Rest)
5. 126-miles/day by swapping to fresh horses ever hour for 16 hours, assuming a race that needs 8-hours to Long Rest, and the multiple of 6 format
6. 162-miles/day as per #4 & #5, assuming Elves