Would it be better to temporarily lay vinyl on a carpet, carpet underlay or floorboards?
Vinyl flooring will fail in short order if laid over something soft like carpet or carpet padding. It's not designed to flex and stretch as it will under foot traffic and furniture, and more concentrated point loads will simply tear it. It'll also wrinkle as it moves and stretches, creating trip hazards.
It must be laid, even temporarily, on a hard surface.