We were a family of three (mom, dad & 8 yo) Definitely too tight to all be in the same row. My son & husband sat in front, me in the middle and a another mom and her son in last row.
Don't do it! We did it last year with 2 adults and small 9 year old and it was tight! I would have enjoyed the whole experience more if we had more room!
Honestly speaking it may be too tight. My hubby, son and I went when my son was 5 and we are not thin people. Hubby sat in the back and the son and I sat in the front. It may be tight.