After promising myself I wouldn't, I made another attempt at battling Zygarde in Dynamax Adventures, not really expecting much, and......
I ACTUALLY CAUGHT IT!!!!!!!!!!!!
I was using a Sneasel, and the team I ended up with was Nidoqueen, Klinklang and Chansey. I Dynamaxed on the first turn, and Sneasel's Max Hailstorm did a surprising amount of damage, enough to get Zygarde into yellow health and trigger Power Construct. It wasn't even a critical hit or anything. While I know Zygarde is 4x weak to Ice, I've never seen Max Hailstorm do that much damage to it before.
On top of that, the AI on Zygarde decided to be dumb for the first couple of turns, using Max Strike on Chansey and Dragon Pulse on Klinklang, which they tanked, and the hail from the Max Hailstorm wasn't causing a lot of problems either. Meanwhile Nidoqueen kept spamming Charm, so when Zygarde did start using Land's Wrath, its Attack was too low for it to sweep the team. By the time Sneasel's Dynamax wore off, Zygarde was down to only a bit of red health, and while we only had one life left, the rest of the team had just been revived and were all at full health, so it just took one more Triple Axel to bring Zygarde down.