Just wondering what I should be packing for a give day trip!
Check the weather, but since it's probably going to be cold, the best solution is to dress in layers and wear comfortable waterproof shoes.
Layers. Lots of them! I really feel the cold but I go with thermal socks and underwear under jeans, two thermal base layers and several further layers of t-shirts and jackets (at least six layers in total), and snow boots. All in all I cope with the weather quite well when I have that many clothes on!
We have been several times in Feb with varying weather. We've had mild weather and snow. As said before plenty of layers. One of the most important items is a good pair of shoes/boots, there's nothing worse than cold wet feet. We purchased ski suits for the kids and they ended up being the best purchases we'd made( get 2 piece sets, if t's not too cold you can just wear the jackets). We too are in Disney this Feb and will be monitoring the weather forecast.
I can only second (and third... :) )all the above. The weather in France is very unpredicatable.
Christmas 2015 we had lunch outside, it was 17 degrees Celcius and lovely weather.
Last Christmas it was literally freezing and we kept going back inside to get hot chocolate to warm up.
So - layers, layers and layers: that gives you the chance to add another one or take one off, all depending on your feelings that day.