I saw some movement too, but I don't think it's a prop balancing issue.
My first sUAS was a P2V which had a simpler gimbal than later dji products and the H480. Indeed, the H480 gimbal is known to be one of the better gimbals among consumer and prosumer UAVs. So the H480 gimbal should show no movement in 20MPH winds...it can easily handle such winds and stronger. The reason why I mentioned that P2V is that it showed similar movements in video but even more pronounced. This was because it had only a single axis gimbal (which wasn't that responsive anyway) as apposed to the three axis quick acting gimbal on the H480.
Now, I noticed that you have the camera pointing quite high up rather than it being angled down. This could be limiting the relevant gimbal axis in the 20MPH wind (which could have been stronger at the altitude you were at) and so producing the less than ideal steadiness I would expect from a H480 gimbal...this is just a theory of mine and I stand to be corrected. That, coupled with cold clunky hands could be the problem.
Edit: just took another look at the video and now I'm not so sure about what I said above. Have you checked the dampeners? There's something going on and it ain't down to cold hands.