The rule of thumb I was taught is that a puppy can only wait an amount of time equal to their age in months plus one. So, at eight weeks old (two months), your pup can hold it three hours tops (1 month + 1 month + 1). You should probably schedule a couple of potty visits outside during the night, even though it will be a pain.
When we got Cosette, my wife and set a timer for three hours and three hours beyond that. We took turns taking her outside. At twelve weeks old, we were able to lengthen the time between breaks to 4 hours, then 5 hours at sixteen weeks, etc. It's tough, but it will keep your home (and her crate) clean!