At the end of the story there are only 4 possible results:
a) recessive austerity to try to reduce debt and make it sustainable, benefiting creditors but hurting most of the poor and medium class people
b) turn the debt into a sort of perpetual with QE as long as it is possible

c) cretaing unexpected inflation to erode its real value
d) some form of financial repression and redistribution (wealth tax, restructuring, or default, capital movements control)

Still useful for understanding the general framework
"The Liquidation of Government Debt"
Carmen M. Reinhart and M. Belen Sbrancia https://www.imf.org/external/pubs/ft/wp/2015/wp1507.pdf

and also this thread https://twitter.com/t0nyyates/status/1260498501819076611?s=20