I am aware of the lack of interest.  I've actually found the fan base for the Valkyria Chronicles as a roleplay setting to be... extremely limited and we never seem to find each other.  But, the more refined and strengthened an idea becomes, the odds of it attracting attention go up too.

I actually had an idea inspired by Valkyria Chronicles that I've been working on lately.  I won't try to derail your concept, it's solid as it is.  But, I was thinking of incorporating tropical and arctic conditions with a large atoll and an associated archipelago as the terrain in mine.  My concept involved a little bit of a time skip and some balance changes too, including an early propeller plane air force.  But, I digress.

For practical purposes, unless you want to set it up as a tragic story of a failed evacuation, limited resources require a source of replenishment.  Though, that tragedy angle might be something to look into.  There's a large fan base for tragic and heavily dramatic storylines.  If you took the core elements and moved them out of the fandom niche you might find a bigger audience.