Toto also had that problem .... our vet showed us a little trick. I believe I still have pics I posted ... anyway, band the tail and on either side up near the top of her back. Looks like she has three little "ponytails"!
I also trim [with scissors only] her little butt and her little "tee tee" area. You can also trim [again with scissors] the long hair inside her legs and on her belly a little shorter. Toto absolutely will not step in her urine and will not pee on a pad but once!! "Miss Prissy Paws" doesn't like to be stinky!! BTW her coat is also floor length. Can't find the pics but will try to find thread where I posted them.
I also use the puppy bath wipes or just regular baby wipes when necessary.