Even with extended hours at DAK, it still closes early enough that they could get the Yeti out without having to close the ride. All they'd need to do is make up a temporary non-moving Yeti (that would be no different from what they have now) and switch them out overnight. The ride would never have to close, very few people would know the difference, and the repaired Yeti could be put back in when it is ready. I'm sure it's a question of funding, rather than effort and planning. It will cost money to fix such an elaborate AA figure as the Yeti and, right now, all the money is going toward the major refurb of Epcot and DHS.