Lace Detail Off the Shoulder Sheath Gown

I usually wear a size 6 but ordered an 8. I’m 5’6” 135 lbs (lean toward pear shaped). The top looks great and fits in the waist; very flattering. The silicon strip does a great job of keeping the sleeves in place: looks so nice just off the shoulders. The ruffles accent this dress nicely and give it class and character. The problem starts, with me, at the slit in the bottom portion. The slit goes to about mid thigh (maybe a tad higher) and travels up even higher when sitting down and falls open when crossing my legs. It’s visible also when standing and no hiding it. There’s plenty of stretch and room for movement without the high slit. Maybe this dress was designed for a slim build. The length is too long and drags on the floor a little too much for my height. If I decide to keep this dress I will have to alter the slit and have it begin about 3 inches above my knee and hem it.