To double tape or not to double tape, that is the question...
The whole bar?
The tops only?
The drops only? On the basis I don't have crosstop levers on the tops and will consequently be on the drops to maintain the ability to brake on the descents and will only really be on the tops (and hoods) on climbs and on-road.
I'm not sure but can certainly help out if you need to know which hand to wipe with 
I've done the 3 peaks a couple of times and there's not much on the course that I've thought "Another roll of bar tape would make this nice and comfy" about 😉
The descents are so mental that your entire body'll be getting battered and your hands will be cramping up from hauling on the brakes soooo hard...
I'd agree with twinkly...
Wearing some BG type gloves/mitts works better. Find some you like and wear them for training.
Suits me then, one less thing to have to sort out. Was just on the basis of reading Dave Haygarth's 3 Peaks blog...
Hmm... Left or right hand? Doubt I'll have much chance to wipe if I'm hanging on for grim death, it'll just have to roll down my legs and collect in my socks and shoes...