Instantly toggle all collections/objects inside of another collection. This will help free up memory by turning off visibility in both the viewport and rendered mode. 

By highlighting the collection (so it has a blue highlight) you can then hit Shift+Q to make all viewport/rendered visibility toggles match your collection and also give them a keyframe. This was developed with Archviz in mind, so that you can let a render go overnight and it will help get your under your GPUs memory limit for fast renders. If you hit Shift+T while a collection is selected it will remove all keyframes in that collection.

IMPORTANT NOTE: When hitting SHIFT+Q you must actually have the collection selected. If the collection does not have the BLUE HIGHLIGHT then it not selected and an error will appear. Hovering does not count as being selected.

IMPORTANT NOTE: Mouse must be hovered over the outliner for the hotkey to activate.

If you try to install the add-on's zip file and it doesn't work, try removing the .py file and then install that directly. I have to put it in a zip file for Superhive but all that is in there is the .py file.