Since your cabins are now close together and your intention is to consider your father's comfort, if it were my father I'd forego Blu and dine with him in the MDR with a specialty restaurant in the mix. Considering his advanced age and health issues I'd feel terribly bad knowing he is dining alone...even one night would make me feel so guilty..how could I enjoy my dinner in Blu, which BTW is not worth all the hype IMO. Since you have 94 cruises by your signature, there's probably more to come. Next time book Aqua again but cruise/dine without the angst you're feeling now. He must feel bad as well that joining you is causing you this concern.