Brakes seize up and stay on after driving for a distance, especially in hot weather. They release when cooled down. Is this the master cylinder or calipers? Car is in good shape at 100 K. Garage kept all these years.

Jack car up, spin wheel, then apply brakes, and release and try spinning wheel again. If it doesn't spin just as easy, try cracking bleeder screw open, then try spinning wheel. If it spins easy after you crack bleeder screw, tighten bleeder back up & try same again. If same result, wheel spins when bleeder opened, then I'd replace the 2 front flex hoses that attach to calipers. If caliper doesn't release then you need to pull calipers and check if partially seized, or maybe slide pins that caliper moves on (that attach caliper to spindle) need cleaning and lube applied to allow calipers to move back & forth.