I make an annual trip to see the Biltmore House in Asheville, NC (luckily only a couple of hours drive away) decorated in all its elaborate beautiful splendor. That fulfills 90% of my need for seeing a house decorated for Christmas.
In my own house I must have a live tree and I decorate it myself with my favorite ornaments. I also put out a few other favorite decorations and a couple of poinsettias. DH usually puts lighted decorations outside. I never start before December 1 and usually don’t get the tree until mid-December (getting harder and harder to find one though) since we leave Christmas up until at least New Years Day. By the time my 3 boys were in high school they stopped helping with any decorating because of being so busy with school and other activities at that time of year. They also really didn’t care what the house looks like as long as there’s food in the fridge. It’s only us for Christmas, though, so that reduces the need to decorate for others.