Anyone Successfully Go from Floor Standers to Bookshelf Monitors w/ Subs?

My system is in a Large Living room which opens to dining room & Kitchen. I figure about 6k cu ft. I have Silverline Sonata speakers now with subs. Unfortunately I did not build my addition when I should have 10-15 yrs ago. Now I'm not really up to the task. Too old & wore out. So I'd love to make the LR a prettier room for my wife. One thing we talked about was the large speakers, and possibly using Watkins Gen 4 monitors. But as good as they sound, I am concerned about the ability to fill the room, or at least my listening area. As I understand, it is about moving air. I cannot see how a 6.5 & 1 inch speaker can move as much as a 10, 7, 3 & 1 inch. So I am quite concerned about that. Right now, the system sounds very pleasing to both of us. We don't want to take a backward step but can live with a sideways step if it is more visually pleasing.

Has anyone made this kind of a step from floor standers to monitors, both with subs, in a large room, with success? Or am I thinking correctly about the small speakers inability to move the proper amount of air for the room size? Thanks for your help.

OH, FWIW, The addition may not be completely out of the picture. But it depends on whether I can get one of my previous sub contractors to do a large part of it. 
No difference at all if set up correctly with tweeters at ear level. There are very few floor standers that will go as low as good subwoofers so, given the choice I would go with stand monitors and subs. But, floor standers with sub could potentially be the same. I depends on the coloration of the speaker. Digital correction and subwoofer management is an excellent idea. All my friends that have heard my system all have eventually add digital correction to their systems and nobody is complaining. It makes getting subwoofers right so much easier.
Why not? I went from Daedalus Ulysses with a REL Stentor III sub to a pair of upgraded Buchardt S400 with the same sub. Smaller room required smaller speakers. 
I would suggest a pair of speakers that are designed to be put into the corners of the room. The Audio Note AN-E/LX HEMP might work for you. I realize that these are not bookshelf speakers nor would you need a subwoofer, but being that they are designed for corner placement your wife might accept that as an alternative. I know they will sound good in a larger room and they come in a lot of finish choices that should appeal to your wife,
The advantage with subs (depending on sub quality), is you can place the bass drivers where they perform best in your room, which is usually somewhere other than where the mid and treble speakers perform best.

Subs and monitors take more effort to dial-in, but, the results are often superior to floorstanders IME, especially when limited by a budget of a mere mortal.
The smaller stand mounted speakers I have heard do not seem to carry the same gravitas as larger floor standers.  My stand mounts have dual 9-inch woofers each crossed over at  360Hz to a 6-inch midrange and they do just fine down to about 40Hz where the dual subs take over.
One question for the group is whether there is a benefit to getting the woofers up higher away from the floor (i.e., stand mounted speakers vs. floor standers).  When I went from moderately large floor standers to my current stand mounted speakers, the bass cleaned up considerably, which seemed to add resolution throughout the entire frequency range, without sacrificing body or fullness.  The deep bass (below 45Hz) from the subs is also better controlled and cleaner, and probably deeper too, than what my previous ported floor standers provided.