OP here. Thank you all for the information! We're not on a strict timeline so we have time to check out the neighborhoods. And point well-taken, I know I'll have to compromise on lot size, but hope to find something with a nice backyard even if smaller.

Thanks!

Woodside and Woodside park have .25 acre lots, but not in the $600k range. Further out New Hampshire ave or near springbrook high (sorry don't know those good names) have larger lots.

We have sidewalks in Northwood and Forest Knolls. Lots are .20 generally. There is one house for sale with a couple of acres
http://www.mrishomes.com/homes-for-sale/MD/SILVER-SPRING/20901/507-DENNIS-AVE-77653393

Buy it and subdivide. It is the original house for the neighborhood. 1890.