Furniture dollys are on sale right now for $9.99 at Harbor Freight. Heck, the good, solid hardwood ones are only $29.99 each. Buy a couple and try them. You'll never know without trying.
You've got 2 potential issues. Mechanical connection with the floor and additional height. Not sure how you resolve any potential issues with the mechanical connection. However, the added height may be mitigated by a bit of forward lean created by a wooden doorstop wedge inserted below the back center bottom of the speaker. The wedge would allow you to easily try different angles.
As also mentioned furniture sliders work wonders on carpeted floors. 4 of the large round sliders would allow you to move those speakers much more easily and would not add any height.
Good luck! Love the speakers. My current speakers are Infinity RS1.5 from 1980