Time can stretch and squish and follow physical rules, if the passage of time is an experience of the mind time itself would remain existent without minds just as real as distance and the passage of distance via movement between objects would remain without minds.

One interesting thing I heard is the DESI data from a telescope observatory in Arizona that was trying to build a more accurate map of the universe identified the dark energy acceleration as slowing. That could mean if the trend continues eventually gravity will overpower dark energy and everything collapses back together again. I don't think it's conclusive, but it is evidence maybe heat death isn't an ending phase.