A +15 offset will never work on an Accord, either will +30.

If you want big wheels, I'd say you should get some 19's with a width no greater than 8" and tires no wider than 235, and an offset somewhere between 40-50.

Personally I have 18x7.5 in a 45 offset with 225 wide tires, and the wheels and tires fit inside the wheel wells decently, no rubbing.