Planning for a trip to Taiwan, my baby will be 6 months then. Is it advisable to leave him with my mom who can help to maintain his current routine but she's not the main caregiver so I will be worried and wonder if I will even have fun with hubby. Should I bring her along but her routine might be messed up since we might be out late at those night markets?

If I were you, I'd leave my baby as well as my worries behind. After all when you were a baby, your mum looked after you, what more her grand-daughter? Plus grandmothers are well known for showering their grandchild with lots of love and affection. In future, you won't be able to spend a lot of "alone" time with your husband. So I advise you to enjoy it while it lasts! :-)