Shortcut to enable automation

I have a series of "personal" automatons that run one every two hours. They get the current temperature from the weather app, and if it's below freezing they turn on a heater out in my well to keep the pipes from freezing. If the temp is above freezing they turn it off.

That's all fine. But I've been working on a single automation that checks the forecast once a day and asks me if I want those automations to run. It pops up a menu with "freeze forecasted, run automations?" I want to be able to click "yes" and have it enable the automations which do periodic checks.

Is there a script somewhere in the Shortcuts app that toggles a personal automation on/off?

And why can't home automations get triggers by time, and then begin by checking the weather? The scripting options for checking the weather only appear in "personal" automations.