Re: Long haul travel for kids
I have taken my kids on quite a few LH trips (with work) - and as you do not get a trip that is longer, most have been a week. Cannot say that I have seen much problem with it. Not sure of the stats but we certainly take lots of Kids LH at Half term, some of who are out of school for a 2 week holiday, but also many just for the week, you also see Americans a long way from home and they get so little holiday that is often only for a week.
As far as hot shorthaul goes in February, you still need to go for the longer SH flights, Canaries can be OK but for more reliable heat I would probably aim for Egypt - Hurgada or Sharm el Sheik, but that time can still get some cool days (As can Florida!).
(What vintage machines do you have? - one of my own interests, just not lucky enough to own any).