Our habaneros are probably 18-24" tall, and spread about 12" wide. We got plenty of habaneros to make salsa, and I put probably 30 in the freezer to use over the winter. 4 plants, and hubby was pleased with their taste. They're an orange variety.
What helped this year was to start them indoors, under grow lights, and on a heat mat. They sprouted in less than a week! Before, I've started them in the green house with the other seeds about April 1. When I did that, I had about 3" tall plants to put out by the end of May. This year, they were nearly a foot tall by transplant time.
I tried to overwinter one once... nope, it died. I've read that of the pepper plants, they can be very difficult to get through a winter.