A couple of options, both close to Tysons Corner which has food and parking for the rainy/cold days and is easier to get to than Springfield (unless you live down there
) I've never been to either to know if they have grills, tables, etc. Map attached.
Scott Run Community Park/Westgate Park
Lewinsville Park - Chain Bridge Road, McLean. Located off of Chain Bridge Road in McLean, Lewinsville Park accommodates all of your fitness needs while offering a fun and healthy atmosphere. The park provides football and baseball fields, basketball and tennis courts, as well as countless hiking and fitness trails and playground areas for the kids.
Or further north, there's Cabin John Regional Park right next to Montgomery Mall at the intersection of 270 and 495.