Should I graduate to floor standers or will larger bookshelves suffice?

Hey guys,
I moved into a larger space several years ago, more of an open floor plan, and soon realized that my current speakers, Legacy Studio HD, in a surround array, might be a bit overwhelmed. It’s a weird, asymmetrical space, but it’s also significantly larger than my previous one. So the title of my post says it all…can I still get adequate coverage with bookshelf speakers, or do I now need floor standers? A friend told me to basically “sit closer to the tv” but that isn’t practical.

I thought about the Calibres from Legacy as an option, which is about my price range…up to 7k or so. I also see all these great internet only brands, like Fritz, or Philharmonic, etc, and I hear about their prodigious extension and sound stage, but can these bookshelves fill my room, or any room for that matter?

Let me also add, I have no problem graduating to floor standers, so suggestions are also welcome.

Thanks in advance.