Surprisingly, a lot of the larger casinos keep their pools open year round and are "heated" to 75 degrees, which is far too cold for me. (I have a pool at home here in Las Vegas and won't even dip my toe in unless it is at least 82 degrees, and that is in August!)

So, yeah, I suppose if you find that 75 degrees acceptable, I believe Mandalay Bay, MGM, Bellagio and a few other locations are technically open year-round..but I doubt seriously you will be lounging by the pool New Year's week...unless global warming really kicks in this year.

Last year in December, a part of our pool had a little sheet of ice in the corner in the morning hours, just to give you an indication of the weather that time of year. We even had snow last year - OK, it was for a grand total of one hour, and we quickly made a tiny snowman and took pictures before the snow all melted minutes later, but still...

I read somewhere that there are a couple of indoor pools at some hotel chains off the Strip - but I believe they are somewhat far from the Strip and the pools are rather tiny. I will look around to see if I can find where.

As previously mentioned, the only real exception is the Tropicana that I believe really heats up a small section of their pool in the winter to a realistic warmth, but it is an adults-only pool, so if by "we" you mean adults, you might want to check into what they have to offer.

Now, should you want to snow ski instead, there is Mt. Charleston, a 45 minute drive from the Strip and quite beautiful up there.