Not sure spare tire would be cheaper, but couldn't that be used short term? Spare would fit better on 16x4 rim right?
Yeah, those temporary spares would fit better on the narrow wheel, but are just as expensive as REAL tires. Visit a wrecking yard and see if they have some chevy 6 lug wheels and tires that you could bolt on. Probably cheaper than buying new temporary tires that you really can't use.
Maybe there's a Bolter near you who would loan you a set of wheels/tires to use. Try an ad in the
Swap Meet.