Fasting is supposed to help free us from worldly cares, isn't it, to help us to live IN this world but to not be OF this world. If we're complaining about it, doesn't that defeat its purpose?
As for Thanksgiving, I think it should be on a personal level -- I hope our bishops don't issue a "special dispensation" for Thanksgiving. I grew up Greek Orthodox, and as you know, Greeks don't always take fasting too seriously. Now that I'm older and I know the importance of taking it seriously, I think a "vegan" Thanksgiving is entirely feasible -- It's important to give Thanks, but why do we have to do it with Turkey and gravy?