Hi Alex. There should be several posts regarding Petiolaris care on the forum, but if not, here's a quick summary of what has worked for me.
I keep the hairy woolies like D. ordensis, lanata, paradoxa outside of terraria, meaning they are growing on a growrack just inches away from fluorescent lighting with no glass sides or top. Standard room humidity works fine. I water using the tray system, letting it dry out before watering again.
The others that I grow of the complex (ie: falconeri, petiolaris) need higher humidity levels under my care. Another grower has excellent results outside terraria for these kinds. I have yet to manage this. They are treated just like the hairier woolies except that they are covered in a clear plastic dome lid with vent holes.
Dormancy is somewhat tricky, as one might expect. I've been lucky as I've had few if any loses this way. Just water more sparingly, and let it dry out for a few more days between watering. That's all I do... not much of a change, but don't force it to grow. My lighting is 16 hours in summer, and 12 in winter, with a gradual change between the seasons.
I use a standard Drosera mix (equal parts peatmoss and petlite). Just make sure to rinse the media well.
hope this help,
Homer