Above a certain level in my agency managers have to designate an official delegate when they’re out, which can easily result in out of office messages like what you’ve listed. Not the most elegant, but clear and useful!
It all boils down to honestly assessing your situation, deciding what degree of contact is appropriate, and then stating your intention clearly and succinctly.

Our office will remain closed until the end of this week for Thanksgiving Holidays. We assure you that all your emails will be answered as soon as we return to the office. Happy Thanksgiving!
I used to work at a place where we would occasionally send reports of network misuse that sometimes included inappropriate images the user had stored on work devices. One person had an email system that was somehow set up to make any attached images the profile pic for that account. So she would end up with random pornographic images as the profile pic whenever she received reports from us. She said she had no idea how to change it and could we please help? Since she was not part of our company, and I have no idea how that could even happen, I just started sending her kitten pictures after every report that included an image. Problem solved.