Yes, that is a pretty close match, except that we don't do the long walk, instead opening our tree presents over coffee after lunch (so about 2 or 3ish). There's no specific rule about the television, and it quite often does get switched on in the late afternoon, by which point people are alternating between sitting around playing with their new presents in the lounge, and helping out with dinner (usually timed for about 7ish). This year, though, I don't think it did happen to get switched on at all, except so that I could tape Harry Potter, which was on while we had our dinner.

Oh, and good on you and your sister for managing an argument-free Christmas, by the way.