The good news is that some courts are beginning to agree.
The bad news is that the DMCA still makes it illegal for you to use third-party garage door openers. See page 63:
THE COURT: ... Isn't it a logical conclusions from your argument that your client's customers are all in violation of 1201(a)(1)? ...You decide! The RIAA and DirecTV people have certainly shown it can be done.MR. FINK: I would say under the statutory language that's true.
THE COURT: Do you intend to bring an enforcement action against those customers?