3 Answers

Keep it well watered and you will get away with it.  I have friends with their trees up already.  I always have my tree down on or before January 6th as according to my Mother January 6th is the twelth day of Christmas... if your tree is up after that it is bad luck!

Seasons' Greetings!

I would ask the attendant where you purchase your tree.  If the attendant doesn't know (and I would be surprised if he/she DID), speak to the manager for the info.  
I think it would prolong the life of the tree if you placed it near a window that you could open a bit and allow the tree to stay cool.  Keep it away from heat.  That will dry it quickly.
I once had a tree up well into February.    That was a little too long for a number of reasons.  I also once had a very tall tree (23 feet).  The lower part stayed pliable, but the top was quite brittle.  (Heat rises) 

You would need a tree with a good root with plenty of acidy soil  of a ph below 4 they do not like LIME in soil and well watered should not lose the leaves or spines and put back in garden with soil with the same ph under 4 you can reduce limey soil with flowers uf sulpher or sulphate of amonia if the soil has a PH greater than 4 and keep taking readings on your meter until under 4. Seeds will not germinate to grow these type of trees taken from these cones on these kind of tree until cones are taken after the first strong frost of the winter.