Putting negative delay into a then-card in a Flow

I have a flow that is started at a certain time that turns off my heat pump and my water heater when electricity is expensive. The start time is not the same every day.
I would like to have a function that increases temperatures on my heat pump 45 minutes before the Flow starts. Can this be resolved? I can fix it by starting the Flow an hour earlier and adding a delay to all the then-cards. However, this gets a bit confusing. Regards Peter

Maybe this will help you: Configurable time trigger