Another way to spin that is simply that you explain your successes by invoking equipment. PbtA really kind of gives you the system, on a 7-9 your climb requires an inventory slot worth of equipment, on a 10+ you get away without it. A 6- might involve losing your equipment, that sort of thing.Oooh. @clearstream, I like that option C explanation. Would make for a neat system of inventory management too. Different items could have a different dc and the check could be based on different skills as well.
Do you have a climbing kit? Make an athletics dc X check. Do you have parchment? Maybe a knowledge check. So on and so forth. The more esoteric the equipment especially in context (umm, you are travelling over flat plains, why would you have a climbing kit?) modifies the dc.
Gonna steal that for my next campaign.