This year is the first year I've ordered seeds and bare-root perennials from a mail-order catalogue. I ordered from Lindenberg Seeds because their catalogue, while not glossy, has good selection, their prices are reasonable, and they offer free shipping if you order $40 or so. They sent all the seeds a long time ago (plus a free packet of sweet peas), but the perennials get shipped out later in the season.
When the box of perennials finally arrived, the roots looked reasonably sized and healthy, but most of them were already sprouting. I planted them as soon as I could so they wouldn't waste away, but then an unexpected spring blizzard rolled in. We piled leaves over them to protect them, and we were lucky to get a good blanket of insulating snow that stayed as long as the temperatures were low. Although all the roots should be hardy, I was afraid the new growth (which probably sprouted in a warm post office) would not be acclimated to cold weather.
Now that we're having nice weather again, most of the perennials appear to have made it through the cold. Most of them are green, and many appear to be growing. In fact, the cool temperatures and extra moisture may have helped them settle in better than this hot, dry weather would have. I'll have a better idea how successful we've been later in the year, but so far, I think I'm happy with the shipment that we received. I would even order from Lindenberg again, if I had any money left!