It depends on what you're wanting done. Are you going to want Wilfred to be available to take you around various other times, to restaurants, etc., and basically be your means of transportation? Or are you wanting just transfers from the airport? If you want him to be available fairly constantly, I would make contact maybe a month or so out. If you just need airport transport back and forth, you can wait until much closer. As others have said if you just need airport transport, there are always cabs there, if you can't hook up with him.
As far as restaurant reservations, about a week ahead should be much more than plenty of time. Generally we NEVER make reservations, unless it is for a group of more than 4 people, but we go off season most of the time.
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