Do I need to uninstall the app if I want to disable the widget for a short period of time?

What if I want to "hide" the widget for a while and then show it again after a period of time, do I need to totally uninstall the app?

No. If you just want to hide or disable the widget for a brief period of time, you just have to turn it off or disable within the app's settings and just turn it back on anytime you want. There is no need to uninstall if you are still planning on using it in the future.