Wheel well fire indication in the cruise @FL390? Suitable airport(s) nearby? QRH drills + land seems like a good idea, even if it is most likely to be a false warning. Covering backsides and all that.
Same thing mid ocean or in an area with high MSA could require a bit more thought... You may not have enough fuel to make the nearest alternate without bringing the gear up again (warning or no warning) and if you're over the lumpy bits, throwing the wheels out could take you below the tops quite rapidly.
In the 777, gear down, the fuel flow is approaching twice normal at a slower speed; the aircraft ceiling comes down dramatically (as I'd expect the airframe to do!) There's potential here to create a dire situation out of an uncomfortable one.
You can't write checklists to cover all eventualities, so sometimes pilots have to fall back on logic and experience. I'm not saying ignore the QRH but IMHO you have to be aware of the direction it might take you (down!) before you follow it to the letter...