Should i go to my sister wedding or Visit his family? Stuck in a dilemma

I am a FTM please don't judge me I would appreciate the feedbacks. I am due in April and my sister "wedding" is in May. Only reason why I put that in quotations because they aren't obviously ready at all. They haven't sent out invitations to the wedding or even made any. The only thing that she done was pick out her dress. My man is going to be deploying this year for a whole year. I want to visit his family with my baby (their second grandchild) either may or June. I live in Texas and the wedding setting will most likely be in Wisconsin we will be driving 18hrs and 20 mins which is a long time for a baby just to stay in the car seat. My sister fiance forbidd to think about my sister extended family and only think of his side of the family who lives in Wisconsin. He states "we are use to traveling" and his family persuaded him to have the wedding there. If I go to Miami it will be on a plane which will be 2 hours. I am stuck in a dilemma 🤦 my family forbids me going on the plane because there will be to much "germs" and says she will develop RSV if I go to Miami but, won't if i went with them..