Yeah, that looks really awkward, and it would drive me nuts.
Unfortunately, as you already know, your options are limited. A whole new floor would be a couple of grand and a lot of work. So, I think I would probably look for a new, bigger kitchen island that can be placed parallel to the existing cabinets yet still cover the existing gap in the floor. If you do a Google Image Search for “kitchen island,” you’ll surely find loads of creative designs, styles, and brands to choose from.