vim quickfix list: manipulate location?

Sadly Vim does not have a concept of a project drawer just windows (splits). After using a command to open the Quickfix list, e.g. :copen or :cwindow, it would probably be best to close then open NerdTree and Tagbar. Something like this:

command! Copen copen|NERDTreeToggle|TagbarClose|TagbarOpen

Note: I have not tested this command as I do not have NERDTree or Tagbar plugins. This also focuses the Tagbar window which is probably undesired.

Alternatively, you may want to look into simplifying your workflow by keeping both tagbar and nerdtree closed unless you are using them. This can make sense for some workflows as needing to see either the tags or file structure can be relatively uncommon (maybe 10% of the time). For tags you can just avoid tagbar entirely and use the :tag command directly or use <c-]> if you are on a symbol. Nerdtree can be used in the same manner as netrw to avoid this issue (See Oil and vinegar - split windows and the project drawer). I talk about these issues in the post: Files, Buffers, and Splits Oh My!

Personally I don't use NerdTree, Tagbar, or anything similar. I prefer to have 1-2 splits open at a time. I use projectionist.vim, a fuzzy finder like CtrlP, :find, or if I really must netrw.

You can force quickfix to open on full width with this code in your .vimrc:

augroup DragQuickfixWindowDown
    autocmd!
    autocmd FileType qf wincmd J
augroup end

It is now what was asked but it is as close to it as I could get.