Ah, the rabbit holes my mind can fall into. A picture Raithe posted in another thread got me thinking...so in The Mandalorian, Din Djarin is a human with a presumably human lifespan. Grogu is 50yo in human years but still an infant to his species. Even if Din lives to old age before dying, Grogu will still be a baby when that happens, so Din will need to find another long lived species to pass Grogu's care onto.
Anywho, time for my third cup of coffee.