The day before Election Day, 2016, I took my Tasha, my 18-year-old calico cat, to the vet because she was sick. The next morning, Election Day, she was sleeping on the living room floor when I had to leave for work. When I got home, I couldn't find her, but I called the vet to ask about her diagnosis. He said that she was suffering from a severe kidney disease and that her life was in danger.
I looked all around the house for her and then found her body in a kitchen cabinet. I had never seen her there before, but she must have known she was passing away and sought out a secluded spot where she could leave the world.
Although I was despondent, my spirits were lifted by the news of Trump's victory later that evening.
The fact that you found her in a spot that she had never gone to before, is that it provided the safety & security it was seeking. A safe space as it may be called. Had your cat been trying to get out when the door was opened? If so, it was seeking that safe space.