Overkill? Perhaps, but those trees never fell over when two 15lb cats chased each other up and down them...
I've always been a fan of the overkill method myself. When we used to get full sized cut Christmas trees, I used a purchased stand (woefully inadequate but it held water) and then attached the tree with hefty screw eyes, one screwed into each side of the trunk about halfway up, tied or wired to two other screw eyes screwed into wall studs. Our trees also were subject to cat attacks but the only victims were a few glass ornaments; the trees always stayed upright. I would think that a bucket weighted with stones would have worked just as well, since my trees were primarily held in place by my tethering-to-the-wall method.
Cut evergreen trees will last a lot longer outdoors in a frozen state than they will thawed out in the heated indoors, so if you plan to leave the tree up for 3 weeks, water is advisable.
(At this point, I guess any advice about Christmas trees is intended for next winter.)