I'm sorry for your dilemma! I understand how frustrating it can be - I learned when I stayed in a hotel with Jackson for a few days. Jackson refused to use pads as a young pup, we did outdoor training from 9 weeks on. I honestly don't think he could ever be trained to pads- he's never been one to potty in a small space. We went camping once and set up 3 x-pens outside and my dads 2 dogs would potty in it, Jackson required to walk and sniff before going.
Personally, I would never go to pads after having an outdoor trained dog. What if you move again to a place with a yard, etc? I know it's more of a pain, but I think dogs adapt well. It took Jackson a day in the hotels but he learned to hold it and we got on a potty schedule. Also, like today it rained here all day so we were lazy and he slept most of the day. He went out at 6:30am, 12:30pm, 4:30pm and will probably go out two more times for the night. That's only 4-5 times per day.
Do you have any kind of porch? That's the only thing I could think of doing is making a porch with a few grass potty patches and making it so they still technically have to go outside. I did this during the big snow storm where we couldnt even walk outside, I let him go on our screened in porch that had a foot of snow on it and he went on it since it was like being outside (with the snow and all).