Advance under duress.. we are CX sarg !! hope this helps

[Oberst Hausser]

In the example above during the Advance Phase - due to the move requiring 4 MP - all units in the stream may not advance to M7 or M8 due to the units (all therein) being CX.
In another slightly different case ( where units need not be CX) in no case may a unit advance if it retains no MF after deducting for portage costs.

NOTE:
A leader: adds 2 to the MF and adds 1 pp to the MMC.

 

[klasmalmstrom]

Looks like they could advance into M8 using the Path.

 

[David Reinking]

The path is your path to exiting the stream now.