If you are actually a business, a common warning that you are near the limit should mostly resolve it. It might only be tricky because the estimated time remaining is really short if it's a huge recent spike: eg. nobody is looking forward to a notice of "you'll use up your spending limit in 4h" on the weekend.

This type of warning should give you enough time to investigate if the warning is real and adjust the spending limits.

But then again, even if you hit them and your services get paused, you'd be increasing the spending limits and restoring services after you are back at work and notice they are down, so it mostly comes down to your incident response times.