Accessibility
There are a couple things to keep in mind when choosing a location. How long or difficult of a hike are you envisioning? Will you have guests there? What are their physical capabilities? If you want to backpack 10 miles to your location and spend the night, will all of your guests be comfortable and able to do that? Decide what is more important to you, the location where you are getting married at or the people you want there. If having your grandparents there is what is most important to you, find an epic location that you can drive right up to! After the ceremony, you and your partner can always continue your adventure by yourself and backpack to another location for the night.
If you want your dog to be there, make sure it’s a location that allows them. Many national parks have minimal to no access for dogs so do your research!