We've been in our 2 up 2 down house for 7 years now. We are definitely starting to notice how small it is as our 3 year old grows. It's a fun area with cool bars and coffee shops up the road but this is becoming less of a draw as we tend to go further afield during weekends as a family.
It's completely possible for us to stay, though we'd need to change a lot to maximise storage and alter some of the botch jobs that have been done in the past (house is around 120 years old).
DH is very inclined to leave but I worry about this - more stress, bigger mortgage to essentially afford an extra box room, still work to do. What made you confident about moving in the past? Or have you stayed somewhere smaller and been happy?