Thanks soooooo very much for your input everyone! Every single piece of advice is Super helpful. If I do decide on adding a leopard tort to the family, it won't be until spring because I'd want to be 100% prepared (and it'd be easier to start when it's not winter).
To answer some of your questions: I live in southern Wyoming. Humidity is usually the biggest concern around here, though it does get quite wintery. Many days my climate's humidity sits at 30%... WAY too low for most torts. I compensate by keeping all my torts in enclosed habitats with carefully-controlled humidifiers that empty directly into their habitats. I also have a misting system for my red foots. At the moment everyone is being kept indoors during winter in large enclosures that I custom-built, but I'm preparing to build a big outdoor greenhouse/heated shed for future winter quarters. I own my own property and can devote the entire yard towards them!