The follower Maurice Jondrelle is very touchy. I had the same ctd when nearing the sanctuary. After some research that returned nothing useful the comment above "That idiot who was following me got eaten by wolves somewhere on my journey" made me think the follower was an issue. When I returned to some saves each time I found he was either stuck and had lagged far behind or was under attack. I was saved at a crash point and able to defeat some enemies nearby releasing the AI and allowing me to continue to the sanctuary without crashing. If all else fails get Maurice killed.
