The usual bogeyman is "burst water pipe." That can come from freezing - or just because. Both are low probability so don't agonize over any of this. But the probability is not zero, so a few simple things:
- There should be a master water shutoff valve for the whole house. Close it, then open a sink faucet until the water stops flowing (so you know the master valve is actually shut).
- 33oF - at the coldest part of any water line in the house - is sufficient to prevent freezing. What you don't know is how well insulated the lines in the walls are, correct? Thus you won't know how many degrees above 33 the inside air temp needs to be. But odds are that 50oF inside air temp will be plenty warm enough to avoid freezing in any of your lines, particularly with the temperatures so far this winter.
- Wouldn't do this for 2 weeks, but if you ever have some exceptionally cold (e.g., -30 or so) weather overnight and are concerned about a water pipe in the wall freezing, allowing a small stream (or fast drip) of water from a faucet served by said pipe can help prevent freezing there.
Enjoy your vacation!