based on the EVgo chargers I have used so far, which is only two, charging from 60% to full would probably take at least one hour, and might take one and a half hours. It can vary because the time depends on how many amps the charging station can supply. The Bolt can take up to at least 125 amps, which a few stations have, but some are only about 100 amps, and those will take longer.
The Bolt charging current drops to a little bit lower rate at about 60%, and drops to a much slower rate at about 80%. And the charging station charges by the minute, so that last 20% starts to cost a lot more per mile than you would pay at home.
The stations in California that I used, did not cut off the charging.