I hate to be a prophet of doom, but we also had a dear little poodle who, sadly died last year aged 10 years. He was never house trained, I'm afraid. He would go outside if the door was left open, but if closed he thought nothing of 'going' inside. My late DH used to be driven mad by it !
I've just 'rescued' a stray from Sicily. He's a border collie/fox terrier cross aged around six months when I got him. He was house trained in a week and hasn't slipped up yet, although he does have other issues like barking at other dogs. Most embarrassing.
Good luck with your little poodle, I hope someone else can suggest something to help.