I asked Grok and it said a lot of people feel the same way. I do not like Thanksgiving as it is now, but I might if it were in October, like Canada has it. We have a controversial holiday on October whatever, 2nd Monday I think, that most of us do not overly care about, but Italians do care and we should not destroy a meaningful holiday. I think we would match with the Canadians. So, celebrate Thanksgiving the Sunday before second Monday. Have your food then, go to church if inclined, play football. Travel on Saturday in beautiful fall weather, with fall foliage in certain areas. No ice on the roads, no snow. Monday, keep traditional (or newer) Columbus day time. Italians will have their traditional day. Next day is Indigenous peoples day. Use either day for travel in beautiful sunny clear weather. Look forward to Halloween. Do not go overboard. Better air travel too in USA.You will have a holiday to do something else with because There already was Columbus Day, which was mixed on and off, and we usually got Th and F off for Thanksgiving.
Now we have 2 holidays instead of (for some people) 3. Make it a snow day for further out.

I can not think of a downside except for very very traditional people. They could still have it the regular day but would have to take personal days.

I think Italians deserve more respect than they are given around this holiday, Native Americans get a special day of respect and far less burnout in general.