Hi..we live in SW Washington...we are in process of getting rid of as
much lawn as possible by putting in mounded island beds....A few trees
(japanese maples) and some conifers will be the base then will fill in
with perrenials and annuals...you might think about the beds and then
use the ground cover as suits your taste...might want to think about an
evergreen groundcover so if house isn't sold before frost it would
still look good...for an inexpensive one I like Vinca Minor, as it
looks interesting even before it grows together...Or a Juniper carpet
type (I like the Bluish green one..but the variety doesn't come to
mind...something blue carpet...(maybe Norwegian Blue Carpet??) Or you
might just go to nurseries in your area and see what they are offering
at good buys this late in season...

Also some hard scape even if only inexpensive oblisks or freestanding
trellis would help fill in areas...Usually at the end of the season
like now you can also get inexpensive iron/wood benches...Fred Meyer
has a darling smaller size (kiddies?) for around $19 that I used to
anchor a smaller treed bed.

Anyway...just a thought...