Alright heres what I bring. First we bring a 3ft prelit tree. Fits in its own box so it dosent take up all that much space. Box of ornaments...they are fragile so I have a small tool box that I use in which I carry ornaments, ornament hangers, spare bulbs, extension cords, holiday nightlight, tree top...ect. Wreath for door and one of those over the door hangers.
Also if your a eggnog fan bring it with you. Our first trip to Disney for Christmas was about 4 years ago and I called to POR before our trip and asked if they carried eggnog. The guy had never heard of it,he even asked someone else there and thay hadent heard of it either.
Some othere cool things I have seen was white lights on the balcony at GF, Lights on the balconys at Swan and Contporary which you could see fron the MK. Candles in the windows at POR lights around the windows at POR.
You might think there wont be that many people who decorate but you will be suprised.
Remember you will need a extension cord to get power over to the windows. A 15 ft cord works great, 9ft will work but its a stretch and you will trip over it all week. Buy some inexpensive ornaments from home, you can buy some from Disney but you will spend big bucks and most ornaments there are large and heavy and just dont work well on small trees.