What happens to the dragon's horde when they die? Do they have children?
Minor note, a horde is a large group of people. The etymology comes from the mongolian/turkic word 'ordo', which was the word for the court/government of large steppe nomad nations (AKA a horde). A hoard is a collection of treasure, and has a germanic etymology. It's just one more confusing thing about english.
Anyway, this is partly up to Roboson, so what follows may be modified if he has anything to add.
Dragons definitely do reproduce. I imagine they only have one child at a time, which is incubated by the mother on her hoard (which confers part of its energy to the embryonic dragon). The father probably keeps in touch to make sure that his offspring is safe and healthy until they can survive alone. Once a dragon has reached maturity, its parents give it a portion of their hoards to get it started, and it flies off to find somewhere to live.
Dragons of sufficient power can live for a
very long time. Mud-dragons (with no notable hoard) don't make it past a century before dying of old age, but the Star-dragons are still alive and kicking, and those are of the first generation (and whilst the timescale is somewhat indeterminate, it has surely been at least a millennia since dragons were first created). Confubrum is also several centuries old, but he is feeling the weight of years, and will probably pass away naturally in the coming turn.
So, what happens to a dragon's hoard when they die? The way I picture it, they can feel their (natural) deaths coming, and may attempt to contact their offspring in order to hand off their wealth. Dragons that die unexpectedly will leave behind a well-hidden stash of wealth somewhere, though.