2.5 year old Brittany pooping/peeing overnight

My dog Lilly is a super smart and fun Brittany Spaniel. She is crate trained and has not soiled her crate since she was she was about 5 months old. She trained very easily. I remember it took about 15 minutes to teach her to speak while I was cooking dinner one day. She also knows sit, jump, shake, lay down, roll over, leave it, down, stay, go and she comes to a whistle every time. When we are home she rings a bell to go out and never has an accident. During the day when we are not home and over night she stays in her crate. If we leave her out over night, 3 out of 4 times she will pee or poop by the front door, which isn't even the door we use to go to the yard. I use and enzyme cleaner and have replaced the padding under that area to a type with a plastic film so it cannot soak the padding any more. But she still continues to do this. I can tell when I get up just by her body language if she has done this or not, so she knows it is wrong and that it upsets me. I know she can hold it because she NEVER goes in her crate. I would REALLY like to leave her out overnight and also during the day so we don't have to have a big crate taking up space in our house. Any suggestions would be appreciated