I also have a 46” Samsung that’s about 7 years old. It’s been a great TV for us. My advice would be to get another Samsung with the latest technology. You’ll find these new sets are much lighter and a lot more energy efficient than your old sets. I would place the new set in whichever room you watch TV the most.
My 46” Samsung has a thick band surrounding the screen. The bands on the newer Sammies are much narrower. A new 55” Samsung is about the same size as my old 46” set. You won’t necessarily want to buy same size set.
I wouldn’t worry about viruses or spying. You aren’t going to be hooking it up to the internet anyway.
It would be a good idea to go to a Best Buy and compare the pictures. They will probably have the pictures in a mode where the colors are over-saturated, but there is a difference in pictures which is more noticeable when they are side by side.
Don’t forget to check out the layout of the remote. My Samsung remote is far better than my Sharp TV.
Good luck with your shopping!