I have only made one long trip with a baby so far, so I am hardly an expert. But I am here to testify that you and the baby can survive, even if you’re as unlucky enough as we to be cramped in regular economy without a separate seat for the baby. Our flight was 13 hours, from Chicago to Beijing.
The most helpful thing we, or rather my husband, did was to squeeze the car seat on the floor below the seats. Some babies might sit quietly on the lap for a time, but mine is not one of them. When he got sleepy I could put him in there and pat him to sleep and then get some unencumbered rest myself. Or eat my food and drink coffee without it or him being endangered. The car seat also helped just for general fussiness as he at times found it soothing.
Unfortunately, while I had snacks galore, I did not have as many toys handy as would have been good. A big help would have been a few new small and not bothersome toys to bring out every now and then. There were times he did cry for a few minutes despite my best efforts, but I hope they were few and far between and am grateful for understanding neighbors.
The two five-year-olds did much better than expected. They were entertained by the personal TV playing Ratatouille on an endless loop. The one enjoyed keeping an eye on the map too and asking endlessly if we were almost there. The good thing about this though was when he could see we really were close, he got super excited instead of being grumpy from tiredness. Requesting kids’ meals is a must – not only do they get better food (might request for myself next time) like fries and chicken fingers, but they get it first.