Henna (Lawsonia inermis) Indoors

I am interested in growing a henna plant in my home but I am unsure of the conditions it would have to withstand. I live in Ontario, Canada, and that means hot summers and cold winters. It is not the hot summers I am worried about, it is the cold winters. Henna thrives in dry hot conditions and they dislike the cold.
I was wondering if I could still grow a henna plant and what I would do in the winter, as I don't have a greenhouse. It also wouldn't help growing them in the house, since they can grow very tall. I know nothing when it comes to growing this type of plant and I don't want to make the mistake of buying henna seeds and then have them dying on me.

Unless you live in a house where temperatures are allowed to drop very low at night – perhaps because the house is heated by a simple wood-fired stove – the plant should have no trouble surviving on a south facing window-sill, as long as the window is double glazed and therefore does not get too cold during cold winter nights.
When it gets too tall nip out the top and wait for side branches to take over. You should have no trouble keeping it within bounds by judicious pruning.