I'm a little late to this discussion, so maybe you've already repotted the sansie (that's what i like to call them, from the botanical name, which is Sanseveria) but here's my input. I wouldn't use a "moisture retentive" soil, this plant is a succulent
. A good potting mix is cactus
soil with an equal volume of perlite added. You don't need to put rocks in the bottom of the pot, sorry if I offend anyone, but that's pretty much of a myth. I live in West Central Florida, where these plants grow like weeds
outside, and they take temps well down into the 40's; several days below freezing will kill them, though. I would just leave it in the house, since you'll have to bring it in for the winter anyway. If you put it outside, keep it in the shade. Basically, they truly are probably the hardest of all plants to kill. Soil that stays wet is the only real danger. So relax, and enjoy
Putting one by the front door is a very old Chinese good luck practice.