It is quite possible that, once the pandemic is over and we return to what will be the new normal, the finances of the nation will still be sustainable. That being said, it's very difficult to say that with a high level of certainty at this point, because we don't know yet what the new normal will look like. We don't know when the new normal will be, and the most important thing is that we don't know what level of government expenditures will be necessary once we cross that awful divide, that awful gap that is COVID-19.
Depending on what the world looks like when we have finally crossed that bridge and have returned to the new normal, it may well be that government finances are sustainable if we are able to return to a deficit level that is much lower. However, it's very hard to predict with some level of certainty.