Well, hey, if the person in front reclines, and it gets too cramped, baby will let him/her know in no uncertain terms by crying the whole 2 hours!
This happened to us on a SHORT 1 hour plane trip from San Francisco to Orange County, CA with our (then) 6m old son. We were returning from a wedding, and it had been a last minute decision to bring him with us (I was nursing him, so I didn't want to leave him overnight). Since we decided at the last minute, we didn't have a plane ticket for him. On the way up, we got lucky and had an open seat in our row, so we put him in his carseat, but on the way back, we were in the LAST ROW, and the plane was 100% full, so there was no open seat. We had to gate check the infant seat and hold him on our lap for the flight. He was NOT a happy baby! He cried the WHOLE time. Nursing didn't help, nor did a bottle, pacifier, toy, etc. To top it off, the person in front of both DH and I decided to recline all the way, and we are SMALL people and it was bad. I could hardly move. I had such a headache. Luckily, the older gentleman next to us was so patient and understanding. The people in front of us kept turning around and glaring, but THEY were the ones crowding us, but we never said anything. I was trying everything I could think of to quiet my son, but what can you do? The only saving grace was about 20 min before landing, we were flying over Catalina island and it was a nice clear day, and I put my son up to the window, and he became mesmerized by the little boats and the scenery outside as we flew in along the coast. Without that, it would have been 20 more minutes of hell.
After that little experience, we swore we would ALWAYS purchase a seat for our kids from now on, no matter what, and we would NEVER take the back row again, no matter how short the flight.
OP: I hope you have a better experience than we did. But, remember, if the people in front of you cause you discomfort, there's not much you can do about it. You're all passengers on the same plane. You can certainly ask them to not recline, but I, personally, would never dream of doing that. They are well within their rights to do so. You guys made the decision to take that flight under those circumstances (which, to be fair, I would have done as well...suck it up in the name of Disney, right!), so you've just got to make the best of it.