(OOC: Technically, I'm sort of bending the rules to allow you to even continue with the horses at all, since by RAW, they'd take Forced March penalties starting after the eighth hour. I'm going to allow up to four hours of walking them before they start taking the penalties, but they won't get sufficient rest to ride again unless you actually rest. Note that four hours of walking the horses plus six hours of forced marching them will result in reaching home. Horses, on average, can remain conscious for five hours of forced march. Any magic you have to aid in this might make the difference)