[strongSwan] Every network except the other side?

[Christ Schlacta]

is it possible to configure Strongswan + IKEv2 using charon as per usual 
in roadwarrior mode to specify that the networks to be accessible across 
the IKEv2 tunnel are to be ALL networks except the right hand subnet as 
it is known to the right side at the point in time of connection?  I 
connect from numerous networks, and would like to be able to browse the 
local network with all traffic beyond the current subnet being sent 
along the VPN.