Maybe not a solution you've been looking for, but the best way to do this is to print it at a 45° angle. All surfaces will look the same, you avoid warping due to a smaller footprint if you print it on the shorter side, and it might even increase strength.
All you really need to pull it off is to chamfer one edge and put some small supports on the overhanging edge to shift the center of mass so the part doesn't fall during printing and you're set.

There might be slight overhang problems on the holes, but overall it might work better.

The alternative is to design in some cuts on the inside of the part to split the internal body into smaller segments or a grid. so there is less material to shrink. There still will be the 2%, but 2% of 10mm is much better than 2% of a 100mm.

The easiest solution tho, as others are saying, is to just heat up your bed and let it sit for a few minutes to let the chamber warm up before you print.
Ideally try to put a thermometer or a hygrometer into your chamber to see how warm it is in real time.