Those of you shuttling your families around, how do you handle O2 altitudes with little ones? Mine are 1.5 and 3 years old. We don't have supplemental O2 in our F but I am considering buying portable system. I don't think either of them would leave in the cannulas (3 year old maybe) long term. We like to fly 11-12,500 when the winds are favorable. Would like the option of climbing into the mid teens. The idea of my kids sleeping is certainly appealing on one level but the appeal fades when I consider that it would be from oxygen deprivation. Perhaps we just need to wait until they're both over 5 years of age? They often sleep above 10K as it is. Any thoughts on the wisdom of exposing them to legal, non O2 DA's that cause drowsiness?