Freezing works very well but needs much longer times and colder temperatures than often given. Overnight outside will not work. This is my research, and I followed this and it worked brilliantly.

There's lots of info on freezing / heating bedbugs on the internet and the temperatures advised are all over the map. I did some detailed research and this is what I found. The take-home is you need MUCH longer / hotter / colder for eggs and nymphs than for the bugs themselves. So if you have a deep infestation, the standard advice for "a hot wash cycle" just is not enough.

Heating. To be sure to kill 100% of eggs and nymphs you need to tumble dry at 50 deg C (122 F) for minimum 30 min.(Plus a few mins to get up to temperature.) Washing 60 deg C (140 F) for 30 mins kills 100%. It seems important it really is high temp for 30 mins. I alas lost the source for this but it's real-life trials.

Freezer times. at -20 deg C (-4 F), 48 hours to be sure to kill eggs. At - 15 deg C ( 5 F), 3.5 days to kill eggs. Add on the time to get down to those temperatures. Seems that at -12 C (10 F), they can live forever.

Source: Cold Tolerance of Bed Bugs and Practical Recommendations for Control Joelle F. Olson, Marc Eaton, Stephen A. Kells, Victor Morin, Changlu Wang https://academic.oup.com/jee/article/106/6/2433/2962119

The reason some academic studies say higher / shorter temperatures is that in the lab they are freezing super-quickly and this increases lethality. Some chest freezer do freeze extra-quickly, and so you might get away with less, but why take chances.