jmtandem wrote:
Numerous times my family & I have wanted to get away during winter month's only to find campsites not available.
Look a little farther south. Quartzsite is wide open all winter, prices are ridiculously low like free for the first 14 days in some places, and you will not be alone. Like minded folks are all there.
It appears the OP is looking for a close in campground for a weekend getaway with their children. Within about 100 miles of Portland is four coastal state parks that are open and offer reservations and first come sites.