That's an excellent question! Preventing your trash cans from cracking in the cold is all about reducing stress on the plastic. Here's a natural, practical approach I've used for years.
First, the golden rule: empty them out completely before a deep freeze. Liquid residue at the bottom is the biggest culprit. When it freezes and expands, it can easily split the plastic. Give them a quick rinse and let them dry if you can.
Location is key. If you have space, moving your bins into a garage, shed, or even against a sheltered side of your house blocks them from the most biting winds and temperature swings. If they must stay outside, try to keep them off cold, wet ground. Setting them on a wooden pallet or a couple of bricks helps with drainage and reduces frost adhesion.
For extra protection, consider lining the inside with a cheap plastic bag before inserting your main trash bag. This creates a tiny insulating layer. In a real pinch, some folks loosely stuff the bottom with crumpled newspaper or packing paper for insulation, but avoid anything that could become soggy and freeze.
Avoid forcing the lid open if it's frozen shut. Pouring warm (not boiling) water around the seal is safer than prying, which can snap the plastic hinges. Also, go easy on overfilling the can in winter. Overstuffed, frozen bags are much harder to remove and put extra strain on the sides.
A little prep in the fall saves you from a messy, cracked bin come spring. It's mostly about being mindful of moisture and giving them a bit of shelter from the worst of the weather.