My 2c says .14b is pretty safe. I think you'd be 14b regardless of if there was a rest after the boulder problem or if it was straight into the .13d. Just means you'd be at opposite ends of the grade range.
Obviously this is just approximate as every route has it's own foibles like does the .13d section have the crux at the start or the end? If it was at the start AND there was a sit down rest after the V10 some might say hard .14a. If there was no rest at all and the crux of the .13d was at then end then some might say easy end of .14c