After 35 years of live trees I went out and bought an artificial tree 2 years ago.
I know! I know! I've always said I would never own an artificial tree, but age sometimes changes the way we think.
When I did have a live tree, I would water it every day with boiling water, I don't know why this works, (melts the sap so the tree can absorb water) but it does. My tree would stay up for 5 weeks. Most of the time it was still in pretty good shape. If you use boiling water be careful not to get burned.