Shipping out of the country isn't the only problem, getting the right import permits and then having to deal with our slow customs and pathetic excuse for a postal service is where the real problem lies. For example I'm a member of NALS, I got my December bulletin in the middle of February and March's is still no where to be seen. Last year I ordered a rose early spring and It was mailed in time for spring planting. It was delivered in August. The replacement I went and picked up was happily growing and blooming in my garden while the original shipment was a mouldy rotten stick.
I agree BB small is not necessarily a bad thing and northern growers can't be expected to ship the same size plants as their southern counterparts but when small takes two to three seasons to become even a double fan there is a problem. I'm not sure how long the plants were stored that I received last year but they didn't grow any larger than 3 - 4 inches tall and this year they are still single, tiny ( in comparison to all others) fans. They were much later to sprout as well (given this spring, not a bad thing). I don't think I'd want to order from too far south anyway as our normal winters can shock and kill plants that are not accustomed to long freezing temperatures. You see that all the time. People who buy all their plants from the big box stores ( HD, WM etc.) always end up having to replace many of the shrubs and perennials brought in from the southern states.