A couple of things:
-It seems like H/S/W & Sloan may have overlooked you because of the number of years of WE you have. A couple of more might help your application (depending on what the rest of your application looks like).
-What do you want to do with an MBA? If you're getting promoted into a manager-level position at a top 5 management consulting firm, what do you need an MBA for? Isn't that a position that people usually seek 2 years post MBA? It seems like you're already ahead of most of them. If your new position has you managing elite MBA graduates, then that might actually work against you in the application process because people may start to question your need for an MBA.
-Kellogg is still an excellent school with a lot of similar opportunities available to its grads compared to H/S/W and Sloan. If you're goal is to get into MBB or go into a different industry, why delay it for another 2 years? You should be able to accomplish that at Kellogg. Does H/S/W and Sloan really offer the education or employment opportunities that Kellogg couldn't get you?