A remote Pi often has power constraints. This answer assumes that you need the requested information for designing a way to power your remote Pi.
I prefer to use an ammeter instead of specs to determine actual current requirements. Although a multimeter can work, you may find an inline meter helpful. This can help you determine your actual current and power usage instead of having to deduce that from specs.
For example, my remote Pi's have multiple sensors and actuators hooked up to GPIO. I choose to power each Pi directly via GPIO 5V and measure the current and power usage with a inline digital meter This particular meter would only work if you power your Pi from 12V via DC-to-DC converter like I do. The linked meter won't measure a 5V source but it should be easy to find equivalents. Knowing the exact power requirements of my remote Pi has helped me plan out battery needs, etc.