Exceeding Inbound/Outbound Traffic Policy (Bill-shocking/DDOS Situation)

I’m planning to go with one of DO’s low-tier plans (probably the 5$-per-month). I’m concerned about exceeding the monthly traffic allowance in a “bill-shock” situation, perhaps a denial-of-service attack, an event I can’t foresee or control. At that point DO will start billing for every extra GB of traffic at a fixed price point.

I understand DO is sending email alerts about exceeding the limits, but it can take time for you to see those alerts and react (hours, or days if I’m abroad with no internet). Missing the alerts can turn into hundreds/thousands of dollars worth of bills. I’m basically giving up any control here over the potential monthly bill, and have no proper tools to deal with the situation…

I would personally want DO to automatically disable my Droplet whenever the monthly cap has been exceeded.

What are the available options to deal with this situation?

Thanks!