I recommend 8" and bigger pots for outdoor growing and Bogs are even better.

Pot Winterization:

Once it starts to get chilly out start decreasing the amount of water given until they are roughly half as wet as they are in the summer. You don't want to dry them out considerably until they are actually dormant.

When they are dormant you don't need to supply them with very much water, or light. Remove them from water trays. They can't completely dry out or they will die, you want to keep them slightly moist. Don't add water unless it is warm enough for water to be water.

Once dormant wrap the pots with bubble wrap or some other material to give them some insulation. Group your pots together in an area that has some protection from the wind.

If 30º F is as cold as it gets than you are done.

If temperatures are going to drop below 30º F then you should cover the plants with some type of mulch. I prefer using pine needles. If you are going to be having a cold bitter wind with exceptionally cold temps I would also cover the plants with black 2 mil plastic until extremes lessen. Be careful not to smash the plants in the pot. You can tie a thin rope around the pot to hold the plastic or use tape. I generally use rope for easy on/off.

The first year a plant spends its dormancy outside you should protect it from nighttime temperatures below 28º F or so. Bring it into the garage or place in a shed. You must be careful not to warm it up to much though. Try to keep it around 30 or slightly lower. Make sure you know how a plant has been raised when you purchase it, some will have already spent winters outside.

Dormancy is required but it doesn't get cold here!

Not to worry. You have two options, both require a refrigerator. If you just have one or two plants and the room in your fridge (not freezer) do the following:
Place a plastic bag over the pot and place in the fridge for 2 - 4 months. You should be able to tell when your plant is ready to go dormant by its slowed growth. Dry the pot out to just moist and treat lightly with a fungicide before bagging and adding to the fridge.

If you are short on space and/or have several plants: Bare root the plant and place in a sealable bag with some damp long fiber sphagnum moss. Place in the fridge (not freezer) as a above.

Mini-Bog & Bog Winterization:

Bogs are pretty easy to winterize. As winter approaches start the drying out process. Again you just want to take it to half or a little less as wet as it generally is during the summer months until the plants go dormant. Once the plants go dormant let dry to just slightly damp. If temperatures are going to drop below 28º F or so then cover with mulch, again I prefer pine needles. Generally a 1/2" layer will suffice. If you are going to have a cold bitter wind with exceptionally cold temps I would also cover the bog with black 2 mil plastic. Uncover when the harsh weather has passed.