Dd was 4 at the end of july last year and around may I had reached this point too. We had done successfully pants off potty training. (basically stripped her naked and set her on the potty periodiclly at set times throughout the day....it worked AWESOME) she was day trained at around 2. That said she had never been night trained and it was driving me batty. I knew it was just laziness at that point because sometimes she would wake up dry come in bed with me but then be wet a bit later...she just didn't want to take herself to the bathroom.
Plus she was fighting me tooth and nail about no more PULLUPS...she hated them lol. said they were for babies etc....So I set myself up knowing I was going to have a week of changing sheets at 3am and started. I would have her pee after story time and then tuck her in. No panties or pjs with bottoms, only night gowns so in her sleepy state she wouldn't forget. When dh and I went to bed at ngiht we would take her in and carry her to the toliet and have her pee and then put her back in bed. she wet the bed a few times...probably 4 out of 7 nightsthe first week and then was better with only 1 accident a week for a while. I think she just really needed to associate that peeing in bed was peeing and the pullup was hindering that by sucking it away so fast...does that make sense? she wuold pee but not really realize it so by having nothing on her she would realize she was peeing right off. She would always wake up the moment she peed the bed as well and never slept through it.
She did really good after the first month and only had 1 accident in 3 months all summer. These days she will occasionally on those weird nights that she up to late, exhausted or has been out having fun etc start peeing, stop and call for us and she will have only done a drop or so and caught herself. She is 4.5 now and yeah its nice lol.