DEAR ANNIE: My parents, brother and I all live several states away, about a day’s drive between any two points in our geographic triangle. My aunt is roughly a central point between all of us and has invited us for Thanksgiving, where we end up going roughly every other year. My mom and I are hosts on the alternate years. I am quite fond of my aunt, but I have a very severe cat allergy, and she has two cats. She goes to great lengths to clean the house, and I go to great lengths to take every allergy prevention under the sun, but still within minutes of arriving, I have itchy, watery eyes, sne…