The large cover at walmart should also work...it fit over my GT with panniers and that thing is bigger than my wee. If you look at the picture below, it's the blue and silver cover on the right.
I have the Wolf from Wal-Mart too. The Large just barely fits my YZ450F. For the V-Strom with Side Bags and a Top Case, you will want the X-Large from Wally World. It's a nice cover for $20. Had it for years now and I really like it. It comes with a stow bag, that all compacts down to about the size of a loaf of bread. It is easy to pack if you wanna throw it on overnight, when parked outside, on a multi-day trip.
DL650K5, Race Tech Forks, Scotts Stabilizer, SuperBrace, Staintune Exhaust, GSXR Calipers, Fastway EVO III Pegs, Givi Crash Bars, Motoagora Bellypan, TouraTech Rad Guard, Givi E21 / E41 Cases, Givi E52 Topcase, Cortech SuperMini Tankbag, Suzuki Euro Screen / Givi Touring Screen, Madstad Bracket, Kaoko Throttle Lock, Suzuki Heated Grips & Handguards, Dual PowerLet Outlets, Pat Walsh Dash Shelf, V1 Radar Locator, Garmin Zumo 550.