Hi Owen, this is exactly the same problem I had (except I didn’t - and never will have the stamina to - bike for 8 hours straight, LOL). see my reply on Kevin’s post.
I’m happy to say that my home button had slowly recovered after more than a week of on-and-off touch-and-go and eventually became fully functional again. the point I wanted to bring here (apart from drying your phone) is you need to do the menu-shutdown trick to see if your home button is back to normal. it seems once the button is detected to have some issue it gets disabled until the phone is restarted in a certain way.
In summary, keep drying your phone, try the menu-shutdown trick every now and then and see if the home comes back. may not work for everyone but can always hope for the best. good luck.