Mayoreo (near airport, more or less) in Managua, has buses to Esteli.
Jan. 5: Travel from Miraflor to Granada via Esteli and the express bus to Masaya, and a cab to Granada. I am still not clear about what time to leave Miraflor, or how all the pieces will fit together. Any insight is MUCH appreciated!
NOT something to worry about at this stage. Wherever you stay in Miraflor will help arrange, I'm sure. Otherwise, just devote the day to traveling, wake up and enjoy the ride(s).
Otherwise, looks good, have a great time!