My youngest was 2 1/2 (a few months off 3) when we did Cape York, that was 20 something days straight in the Jeep and a roof top tent. She loved it, we got home and her first question was "Where are we camping tomorrow". We took a kneck pillow (kids one) that you use on planes to hed provide some support while she was asleep, but we did tend to wake her up for the exciting stuff anyway as asleep all day in the Jeep meant no sleep at night

All three of my kids (now 6 through to 17) have been wheelin since they were little and when we sold the XJ a month back the 6 year old was in tears as she has a lot of memories and fun times in that Jeep so I had to make a lot of promises of new memories in the JK



Cheers
Steve