I many times wrote on forum about height.
As for width: open map details and set width to 0, it means 100% of width. In menu item properties you can override map width, new value (if you wish). In this case map will use all container where it is.
As for height - modern templates have nested divs, and if div is empty, it collapsed and you don't see it (visually). In map case, when map is loading, current its div is collapsed (because not any data in it), therefore if you set height to 0, then 100% height not works due to collapsed div. In this case you have to set height, and if you want to have map, you need to set 100% height for all nested div up to top.
In my demo for full screen div I use my own template without nested divs, and it show full screen map correctly.
In your case, you can have a few resolutions
1 - have fixed height, for example 400 px, and by default you can on map button to switch map in full screen.
2 - you can try to create your own div with height which is displayed block in any case has height (not collapsed), and call plugin here
2a - you can set CSS Name in map details, which change map div class from default to yours, and set like #2 styles to have map div height by styles