I think the first step is to decide whether you want to do the IBE honors program. If you do, then the decision is made since the program is only offered at Lehigh. If you choose that program, I don’t see any reason why you need to go for a 5th year to get the engineering degree since IBE is a specialty in its own right.
You can major in engineering and add a minor in business at either university. If you decide that you really want to be an engineer, then that’s where the real choice between the 2 colleges would factor in.
That’s how I see it.