Everyone has their own opinion of how to handle this situation.
In my case I was very happy being a senior MD-11 f/o. Upgrading to 727 Captain wouldn't have paid very much more and I was getting really good trips. I could have held ANC MD-11 Captain but that seemed almost impossible from the East Coast (and I wanted to keep my son in one of the best public school systems in the country).
With my senior f/o trips I needed a crashpad so seldom that it was easier to just get a hotel for training.
So ... I waited as long as it took to hold MEM MD-11 Captain at 100. I got a crashpad and sat on Reserve for several years (Age 65 happened about the same time, bad deal for me and almost everybody else). At least I was able to hold the daytime Reserve. I had a reliable airport car and life was good.
You don't mention if "your dad" lives in Memphis? Being junior on any airplanes seems like it would be easier if you live in domicile. You also don't mention if "your dad" needs the money or how close he is to retirement (high 5 considerations)?
Personally I always bid for quality of life considerations but I understand that's not everyones priority.
There is no "right" decision. I wish him luck, this job would s*ck if you didn't enjoy going to work ...
