You can try it out, I would not load tires just for that, if you have chains and are on the flat, paved area, it will make a difference, snow, how much, wet, powdery, compacted, ice, and all these things change the amount of traction you get.
My driveway slopes up to the lane, not steep by any means but enough to be a problem at times, also has a curve to it at the end. all depends on how deep the snow is, but I can push snow up the slope with the loader, loaded tires, weight on back and the chains, and underfoot conditions all play a role.
My problem with a back blade would be I lose that heavy cast iron counterweight and what it does for traction. Without chains, it may not do too much, so if I tried to push with the back blade, chains on, loaded tires, its hard to say how well it would work at this location, specifically my driveway, it may work fine in a paved parking lot.
I do know one thing, they definitely need weight added, how much is hard to say.
We had a '64 4000 select-O-speed, and a factory front blade or what was offered, and I don't believe those rear tires were loaded, it did have double ring chains and it did just fine in the snow, I even had that same weight back then, but never needed it, don't recall using it much, it sat for years until I went and picked it out of the weeds, I'd sell the tractor before I'd sell that weight LOL ! I included a photo of the infamous hunk of cast iron LOL !