Frank, the issue is not whether a person follows the instructions! The issue is whether a person has a set of procedures that work: a set of procedures that keep the rose alive. Zuzu evidently has procedures that work for her where she gardens. Instructions are something like travel directions to get from one place in Manhattan to another. There are probably two or five or twenty eight effective ways to do it, given the conditions. And millions of ineffective ways like flying to Peoria, mounting a donkey and going south. It really would not matter which part of Manhattan one wanted to end up in, this would pretty much assure that, without a change of strategy you never would. The crucial thing is having an effective plan. In this case the requirement is that the plant does not dry out.
"Dry out" can mean different things to different people. But from the perspective of the plant, it is how much moisture (water, H2O) held in the cells of the plant. The moment any part of the surface gets dry to the touch, the rose starts losing moisture. So one proxy for "don't let the rose dry out" is "never let the surface dry." Of course there are other ways to do it. I learned this year that if I was to keep a Palatine rose overnight I needed to carefully seal it in a bag, prefereably with extra water. I left just one rose loosely wrapped in a plastic bag and it had lost so much moisture by the next morning it had begun to change color. I'm guessing I will lose it. I'm also pretty sure that if I had done exactly the same thing after soaking the rose for 24 hours exactly the same thing would have happened. So one lesson is that if you live where daytime weather is warm and dry, you want to get your roses into the ground the day they arrive.
Not all rose distributors send out well-hydrated roses with equal effectiveness. Palatine is highly effective at it. Judging from my experience last year, Edumunds is at the other end of the spectrum. Some of the roses I received from them last year were not viable, no matter how long they were soaked, IMO.
I should point out that the rose neither knows nor cares whether the moisture entering the roots is held in the proximity to the roots by a plastic bag, a bucket, a bathtub, a large brewing vat, a hole-free planter, an inverted umbrella, or a hole in the ground. What does matter is that there is enough moisture for the rose to do all the things that it needs to do, like open its stoma to take up CO2, make leaves, canes, and roots, and so on. It starts out being a little handicapped by virtue of the fact that the tiny fibers that make roots most effective are destroyed during transplant processes. So one needs to be a maniac about keeping the roots moist until these fibers develop.
I was able to predict last year which roses from Edmunds were likely to fail simply by noting whether the rose plants in question felt heavy and dense - whether they felt well hydrated on arrival. I complained in one rose formun here long before it died that one Papa Meillaind, though huge was very light, as if desiccated. It quickly died.
Soaking is not the end. It is a means to an end. And there are many good ways to hydrate a rose. Following the instructions is probably a good way. But if you live in a place like I do where springtime humidity hovers aroun 15% for five months straight, and there is no rain, you can soak your roses until the cows come home, but if you do not water like a maniac for at least thirty days after the rose has begun to vigorously set new foliage and grow canes, the rose will die from lack of moisture. My guess is that in maritime Nova Scotia drying out after planting will be much less of a problem. When I lived in NJ I spent very little time watering roses after they were watered into the ground at the time of planting. Most of my losses were from disease, not drought. If you are planting roses where you plan never to add supplemental water, a good soak may be enough to give them the edge they would need to survive. But it would be safer to be prepared to deliver supplemental water for them until they are established.
