I work and was able to potty train Bailey in 2 months - she was reliable in 4 months.
I used the crate for short periods of time and the ex-pen for when I was at the office. The crate must be small and only large enough for the pup to stand up and turn around. When Bailey was in the ex-pen - then all potty bets were off. She peed all over and chewed the pee pads, etc. No problem, I just cleaned up the pen every day (5 minutes tops). She outgrew this around 8 mos.
However, potty training is not about putting the dog in a crate or ex-pen. Potty training is about watching the dog in the house and correcting behavior. We blocked off the family room, laid down blankets and watched the dog. All eyes on the dog! When she started to pee - then we said "outside", scooped her up, tapped the bell and went outside. Once outside we said "go potty" - then praised and treated when she pottied outside. Repeat as necessary - and repeat you will!
Wash the blankets after every accident to remove the pee odor.
If we had to take our eyes off the pup for any reason - (i.e. wash dishes, brush teeth, go to the bathroom, etc.) then the pup went into the crate. If we had to leave the house, then she went into the expen.
2 solid months of watching the dog - and nothing else!! It worked. Yes, these dogs can be trained - but it takes time and consistency. Do not try to multitask - potty train and nothing else or put the dog up.
Good luck