I'm going to drive at the speed limit on a mountainous one-lane road
Why are you going to drive the speed limit?
I'm scared I'll lose control of my car otherwise, and it's very easy for me to get distracted.
If the road is really bad its a good idea to trust their limit and do the right speed. You need to make sure you have control of your car in situations where there are drop offs like that.
I want to be extra safe and careful.
That is wise to do. That is as careful as anyone can be, once your pass the road, you'll be grateful you were so cautious.