I was able to shuffle stuff around in the fridge at the Los Suenos Marriott to store a few of my drinks in there. Also, we had no trouble bringing a pizza back into the room even though I saw verbiage about no outside food allowed...that was 4 years ago, so YMMV. Never saw any charges on my room for the mini bar either.
However, we spent way too much on food and alcohol from the bar as it rained all week and my wife and I were holed up during most of our honeymoon, so maybe they made some exceptions.