Anyone know whether, when Abbey Wood becomes the terminus of
Crossrail, it will close down for any considerable length of time for
rebuilding work between now and 2018, and if so when (ie when is that
whole station going to be rebuilt?)

My guess is that it's too early to say.

Some friends of mine have just moved there and I promised I'd ask here
on their behalf as there's a lot of knowledgeable people here.

Many thanks

Tristán