Handling of Guest's Inability to Reach STR Due to Road Conditions

[Reagen Natho]

How would you handle a guest that was unable to reach your STR due to road conditions or their vehicle's ability?

My STR is located up a steep road on a mountain outside of PForge. My last reservation was my first one that had issues and I know it will come up again with snow and ice this winter. My listing makes it very clear that you will have to navigate a steep mountain road and that I don't refund do to inability to reach the cabin due to road conditions, but how do I enforce that without seeming like an a**hole and getting a poor review? I wish Airbnb offered a trip insurance to fall back on in a case like this.