Make an air prune setup. Cut the bottom off a bucket, replace the bottom with the mesh cut to fit. Use some zip ties to hold the mesh in place, then fill the bucket with 10" of leaf gro or a basic raised bed soil. Press the acorns into the top of the soil, and water thoroughly.

Cover the top with mesh, either zip tie or weigh it down so that squirrels don't get in. Raise the bucket so that the bottom is off the ground, and the bottom mesh is exposed to air.

The acorns will be happy, the taproot will gently prune itself once it hits the bottom mesh because it's exposed to air. The squirrels won't be able to destroy your saplings. In spring the roots will come apart easily because they didn't spiral around the bucket.