Overnight stop off I-90 (Mass Pike) for big rig

We recently stopped at WalMart in Sturbridge, Ma. When you come in using Highway 20 off the turnpike, stay in the left lane on Highway 20. You will turn left into a mall / strip center where Walmart is located, then go straight ahead for a few hundred yards and veer left . You need to drive past the cinema on the left and park in the side lots to the left of Walmart (not in WalMart's large lot). There is a row of bushes separating the Cinema parking lot from a couple of lots belonging to Walmart. No hassle. That's where WalMart told us we could park.