How does Trezor's wallet recovery work if the private key never leaves the device? If the private keys never leave the TREZOR, how can they be restored if I lose it?  I am assuming that maybe the private key is generated on the TREZOR and then encrypted before being sent to SatoshiLabs where they only have encrypted data that requires a few of the 24 words to unencrypt.  Can anyone validate this or tell me how it is actually done.  I guess my concern is that I don't have control over my private key...
The Trezor generates a seed offline on your device. Neither the private key nor this seed are ever shared with SatoshiLabs.

In fact, you're in sole control of your private key: when you first set up your Trezor, you're being shown the 24 words that encode your seed. You have to write these words down and keep them as a backup. When you lose your Trezor, you can use these 24 words to regenerate your wallet by putting them into another Trezor, or using compatible software that performs the same key derivation.