Adaptive Taskbar for Windows is a simple Open Source app that auto-adjusts the taskbar from big to small, depending on the main screen size.
For instance, this app is for those that change between small and large screens frequently, like between a laptop and a smart TV. It works in the background by automatically changing Windows' taskbar size setting when you connect or disconnect your external screen, so you don't have to.
Adaptive Taskbar for Windows is a simple option for keeping the taskbar in check when changing from different size displays. You can test if Adaptive Taskbar works by changing your main screen resolution to be smaller or equal-or-bigger than the threshold, assuming your Windows' DPI setting is set to 100%.