I'm not sure I understand the question. If the B17 fits you, why would you need a wider saddle because you have raised the handlebars?

For what it's worth, I have a B17 on a drop-bar touring bike. I can set the handlebars to be about 2 cm below the saddle and be comfortable. If I lower the bars more than that, the saddle starts to press into my perineum. But I can't see that raising the bars, if that's what you're asking, could cause a problem.