Have you tried a puppy grass pee pad??
It has worked great for us. Chloe would fall of the wagon for a time but it was no doubt due to the ongoing run of visitors this winter. When she would slip up I would put a wee pad in the shower ( it's a large tiled walk-in) and close the door, wait until she went then clap, dance a jig and give her a treat.
She is currently doing very well. It sure helps if you have the time to all your time with them for a few days. After a particularly busy time with visitors and then at one point I left for a few days to welcome my son home from Afghanistan. When I returned home she was sooooooo naughty. Everything you have described. We were back to square one. It took a good week or so of never letting her out of my sight to get to where we are now. She would almost do it right in front of me.. very very naughty. I knew there had been way too much action though.. too many constant changes.
Once things quieted down she improved 100%. I'm not sure how you do it if you can't spend every waking minute with them when they're misbehaving so badly
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I highly recommend the puppy grass pad. Much less expensive over the long run than the wee pads.
No doubt when we head back to Michigan I'll be pulling my hair out again as everything will be totally new to her.
The more time you can spend with them the better is the key I think.