Update: finished the trip in Sept with wife+kids flying back earlier to organise schools, housing etc.
Trip was fantastic and main two issues:
1) should have learned more Spanish before we left - would have allowed us to interact more with locals
2) we were only on the trip one year (2-3 yrs for that route would have been better so we could slow down more and take it easy, see more sights etc.)
Mechanically trailer had some issues (mostly too heavy and several retries on airbag positioning. Truck had an origonal fuel pump replaced in Mexico (few strange intermittent cut-outs at very slow speed) but no issues otherwise.
Will update more as get time including lots of photos (edited)