I find “portemantout” doesn't roll off the tongue. Instead, something like “portemantotal” would sound better.
Also, the defining characteristic of the problem that the words overlap is just not used for portemanteaux. For example: « porte » and « manteau » don't overlap in « portemanteau ». It's still a very nice problem!
Also, the defining characteristic of the problem that the words overlap is just not used for portemanteaux. For example: « porte » and « manteau » don't overlap in « portemanteau ». It's still a very nice problem!