If by refurbished you mean blasted and re-painted or lacquered, probably come to no harm.
At least not if the paint/lacquer is a decent job.
If you really want to be sure, a coat of oil or grease and wash off before use.
And better under a tarp then bin bags...less condensation.

No place to get them under cover?

 

Or in your loft

 

I'd give them a spray with something - maybe ACF50 or a similar motorcycle anti-corrosion spray.

Some are quite expensive, but I've used Putoline PPF52 on the engine casings of my bikes for a few years and have some Muc-Off Motorcycle Protectant too - both cost about a tenner for a can which should do all 4 wheels.....

 

Used to use Fenwicks over wintering product on the caravan and it always seemed to do a really good job. It washed off easily enough after too, but not a mark on the caravan despite it sitting on the drive all winter.
Not expensive either, less than £15 for enough for a couple of winters on a large twin axle van and it’s four alloy wheels.

 

Just thinking - if they are going to be in the garden, even wrapped in plastic or in a tarpauline, maybe put some layers of cardboard down underneath as a bit of insulation from the cold/damp ground.....

 

Probably better with a couple of 2x2s to lift them off the ground?