The older way of dragging a window outside the screen was sending it partly to another workspace because the "window snapping" feature was absent (the one that you experienced: "if I drag a window to the side of the workspace, the window is maximized to half of the screen"). Now, it is enabled by default. Do disable it, install Unity Tweaks Tool: Window snapping: OFF.
But there is another more elegant way which keeps the window snapping enabled by using Unity Tweaks Tool.
This may vary, but imagine that we have two horizontal workspaces and the lower hotcorners set for showing workspaces and spreading windows:
So, we can just go with the pointer to lower right corner to expose all windows and select the one we want to move
And when that is selected, we put the mouse to the lower left corner to see all workspaces and drag the window where we want: