I'm actually opposed to the idea of mixing tobaccos like this -- especially if one is a blend I didn't like on its own. To me, this is like saying, "Hmm. This wine is awful. I think I'll combine it with a really good wine and see if I like that." No. Why would I want to ruin a good blend with a bad one? At best, you'll end up with a mediocre blend that reduces the pleasure of the good blend without significantly raising the qualities of the bad one.
But I'm also a purist when it comes to the blender's vision. I would rather smoke exactly what the blender intended -- for better or worse -- than try to come up with some haphazard, never-to-be-duplicated (or desired) again blend, just to not "waste" tobacco. If a blend is unsmokable to me, why wouldn't I want to throw it out? It's like saying, "Wow, this milk has really gone bad. But I don't want to waste it. So I'll keep drinking it."
No thanks. I've discarded relatively few tins in my life -- maybe a half-dozen over the course of 33 years. But I have absolutely no regrets about it. I'd rather smoke something I enjoy than something I'm enduring just for the sake of economy.
Bob