I never had this happen before. It has been so cold here that we have heated more than usual. The heat has not been turned up, I refuse to do that, but it has turned on more often. We do have humidifiers throughout the house. Two table tops, on in the bedroom and one in another room, and the large floor model in the main room. This has always sufficed. 

Well, I noticed the G string on one my violins, Nick, came completely loose, The A string was not quite that loose and the D and E strings were way out of tune. It usually holds its tune quite well. On my Fiddlershop Concert Deluxe, it was out of tune, but no floppy strings, Again, this is unusual because it holds its tune, also. Then I have my Parker, my violin my Grampa made, it was in tune. Hmmm

The difference? My Parker has geared pegs. The other two violins have regular pegs. I am pretty sure that is the difference.

Nick was due for a string change, anyway, so I changed his strings. The strings on my Concert Deluxe are fairly new, and the strings, although out of tune, not really way out of tune, were just tuned, not changed.

So, I think the geared pegs kept Parker from losing its grip. 

So far, Nick and the Concert Deluxe are holding steady. We upped the humidifyer a notch while we are in the cold spell. We can put it back when the heater is not turning on quite so often.