From Wikipedia:
In the late spring (of 23 BC) Augustus suffered a severe illness, and on his supposed deathbed made arrangements that would ensure the continuation of the Principate in some form,[123] while at the same time put into doubt the senators' suspicions of his anti-republicanism.[124][125] Augustus prepared to hand down his signet ring to his favored general Agrippa.[124][125] However, Augustus handed over to his co-consul Piso all of his official documents, an account of public finances, and authority over listed troops in the provinces while Augustus' supposedly favored nephew Marcellus came away empty-handed.[124][125] This was a surprise to many who believed Augustus would have named an heir to his position as an unofficial emperor.[126]
Would the Principate have survived after him had he only been ruler for a short period of time? Would his death be seen as the gods disapproving of his reforms and centralized power? Who would come after him?