A new-ish, well-maintained vehicle with new tires, fresh oil change etc, if it's left dormant & undriven untouched in a residential driveway for 1 year, will it be driveable after 1 yr?
Biggest thing to know is what sort of climate are we talking about? Extreme heat and cold are big factors. As well as sitting the thing down beneath some big trees or in a very dusty place.
I'd make sure it's driven every couple of months or so.
With a moderate climate the gas and tyres are probably fine for a year. And the battery is probably fine if it's left disconnected and charged up again before putting it back in service. But a year is about the limit, after that the chance of the gas going bad, the tyres getting out of round and rubbers drying out is high.
In a more harsh climate, things can go bad much sooner. Probably better to sell it and buy another one, once you need it again. If for example you are going away for a year or more.
Heat/dust isn't an issue (minus maybe cracking the dash of there isn't a sun shield), it's why all the plane and car grave yards are in the desert. Cold/moisture will kill anything quickly.
About 1/2 as bad for it sitting. Rubber will rot a lot quicker with weather than just dry heat. You're talking about a constant heat with no moisture vs an humid heat + water + cold cycles. It's a lot worse on rubber than dry desert heat is.