The tree can be kept healthy enough to root when planted out in the garden after Christmas (and it won't shed needles all over the carpet!) if you wedge the trunk down among medium-sized rocks or stones in a fairly large metal or plastic tub/bucket and ensure an inch or so of water in the bottom is kept topped up over the holiday. This weight is needed at the base otherwise the tree and decorations will be top-heavy. Those metal tripod things are in my experience not sufficient in themselves to hold up any but the smallest (3') tree.