Part of me wants to tell you that representing BYU there is the best but the other part of me does recognize reality when it comes to yewts. I work on campus every day at the U (for an electrical contractor, not the university) and can see the reasons not to wear BYU gear here. One day I forgot that I was wearing a BYU hat and had a lot of people harassing me over it. I didn't think it would be that bad but I had to take it off by lunchtime when the yewt masses were all over campus.

If it was just you and you were up to the harassment I would say go for it and wear your BYU gear but if you are worried about your family then it would probably be better to just go in something else. I could be wrong and maybe they would have enough decency to not harass your kids but they are yewts so I don't have much faith in it.