You did the right thing to rehome Thor, he was adorable, but rottis can be a challenge. Sounds like he got a great home.

Now, housebreaking....#1 - cover your floors with lots and lots of newspapers at night! Taking the puppy out after eating and every couple hours is good - take them to the same spot and choose a phrase like "go potty" (I use - "go pee") and repeat it regularly in that spot. When the dog does, praise it by name with that phrase " Good Spot! good potty! " or whatever you used. This will help the dog know what you mean and that this is a good thing. We did this with our 5-week old puppy and she caught on pretty quick. I've also heard you can keep them near you on a leash so you can quickly get them out when they assume the position, but you have to be quick!