are their any places in the usa that are still warm enough in january to lie by the hotel pool.

January is typically the coldest month everywhere. Just checked usual warm places on weather.com (averages and records). Seems average high in Miami, key west, los angeles, phoenix - traditional warm climates - in January is 68-73. Obviously you could hit an especially warm or cold spell.

Certainly warmer than montreal, but not exactly beach weather.

Hawaii

On weather.com's site, you can actually put in a desired temperature and it will spit out a list of destinations to choose from.

I put in an average high temp range of 70 to 79 degrees (warm enough to lie by hotel pool, I would think) and it suggested:

Boca Raton, FL
Daytona Beach, FL
Delray Beach, FL
Fort Lauderdale, FL
Fort Myers, FL
Hilo, HI
Key West, FL
Lanai City, HI
Lihue, HI 78
Miami, FL 73
Naples, FL 75
Orlando, FL 72
Palm Beach, FL 75
Palm Springs, CA 70
Pompano Beach, FL 76
Tampa, FL 70

If too cold for you, try a higher range.

how about the US virgin Islands?

US Virgin Islands is a good idea. We were there in December and it was HOT! (in the nineties)

I live in Orlando and it can be frosty cold or hot as can be. You just don't know. We had our heat on this morning to get the chill off, and by the end of the week it is to be very warm again.

Spent an entire week by the pool in the FLA keys last January and it was perfect--low 80s hi 70s.