I haven't been on this specific ship, but my past 2 cruises, I have been in an inside stateroom by choice. I found it was adequate for just me, but two people could be just a little tight. Is this just an "interior" stateroom," or a "large interior stateroom?" The difference I think is about 17 square feet.
You'll probably find that there's so much to do, that you're only in your room to sleep, change, and take a shower. You should be fine.
2007 - Majesty of the Seas (Bahamas)
2009 - Enchantment of the Seas (Western Caribbean)
2010 - Freedom of the Seas (Western Caribbean)
2013 - Golden Princess (Alaska, roundtrip from Seattle)