It can go either way, there are people who said they just started from where it left even after the hard shutdown and in many cases they might needed reindexing which means you have to download the entire blockchain again to get things going.

It's always better to have a backup power or atleast the mini PC inverter which can give you few minutes time to save and shutdown properly, it's necessary to have one not just for nodes but anyone who use PC's to avoid data corruption.