Range and fuel
Your detailed website schedules show what might have been possible in terms of return range/fuel remaining. The doubt about how close she actually got to Howland
is obviously a big factor , it seems she could have just about made it to ENB in your theory- which I see allows 'search' time , but if she didn't get that near to Howland then your range calculations are more comfortable.
Either way, you demonstrate a feasible course of events. I'm astounded the modest funding you need is proving problematic.