when just few cluster nodes are up - no possibility to use shell at all

As already mentioned [0], you can always setup some nodes with higher voting power than others.
I've tried that and it does not really work for my set-up.
The problem is the the quorum is recalculated based on the voting power of individual nodes.
If I increase the voting power for 2 of 5 the nodes, they still need to be both up and running before quorum is achieved.
If only one is running - no possibility to have a quorum.