To be honest, you'l be amazed at how big a screen you can get anyway with. We were looking at "going large" earlier in the year, the calculations suggested that a 50" would suffice. However, the last time I bought a TV it looked massive in the shop, however when I got home it was tiny when in the living room.
So with that in mind, I went for a 55". I can still remember the day that it was delivered, we all sat on the settee literally open mouthed as the two men carried it in and set it up. In fact, my daughter said at the time, "dad you have gone to far this time".
If I am being honest, for the first few weeks, it was indeed that "elephant in the room", but now we all thoroughly enjoy and it was the right thing to do. So if your gonna buy a new TV.....my advice is to go
BIG