Emmy has also grown up w/bi-lateral HD and I also chose to not have surgery. She will be 6 on tax day and has been in training all of her life. We go every Monday and she loves it. We also just control the pain and I just keep an eye on her and not overdue. I let sit "lazy" because it is more comfortable. She also lays w/her hips to the left because that is her "better" hip of the two. I have shortened the distances that she does her recalls and her retrieves because she has two speed, stop and fast, fast, fast!
It can be done and your little one will enjoy getting out and learning! Good luck!