Chrissy we were much the same with our routine and realy worried about going out because we didnt want toupset what we did at night, what we have started to do is if we go out to say my folks for dinner, I will just do our night time routine there and put her in her pram. If we are going out for dinner we just go out later and put her to sleep before we go and take her out in the pram.
I have found if we are out though and it gets past her bed time she WANTS togo to sleep and get very cranky if I don't go somewhere and put her down. We have always managed to get back into routine the next night though