It woulda d depend on whether you were planting Own Root or graftebare root. One generally plants BR earlier as the ground thoawatjtha thaws. Here I plant BR in March April, but Ive done dormant roses as early as February.Potted roses can be planted anytime so long as its not too hot. Ive planted mid summer, but had to shade them a bit and be extra careful with water.

Supposedly spring moves north at a rate of 13 miles a day, or about 2 mph. It slows down for mountains, and can do strange things around large bodies of water, but you get the idea. It isn't really a function of zone, it's a function of how far north you are, and when you hit key temperatures.

I used to be able to find national maps of different temperature probabilities. They were designed for use by farmers. Now I can only find them for certain states. I don't remember if Minnesota was one of them. For planting leafed out, hardy plants, it's 90% probability it won't go below 28F. That is true for most perennials and shrubs, so a good garden center or local cooperative extension should know when that is for your location. People in milder climates will say they should be planted after all chance of frost, but they obviously have roses confused with tomatoes.

Bareroot roses are a different matter. The theory behind them is they are not planted in spring, but late winter. So they go to sleep in one location, and wake up in another, like little kids that fell asleep in the car. It's not a method that is used for many other plants, since other bareroots seem to be planted after they have woken up a bit. Realistically, they can't be planted until the snow has melted, the ground has thawed, and things have dried out a bit after mud season. There are locations where that happens so late, that dealing with bareroots isn't practical.

you could go look at the duluth rose garden to see what you like there. i live in minneapolis and would try william baffin, cherry frost, above and beyond, therese bugnet. you could try some more tender roses as well on the south side of your house. or you can look at high country roses online and set the filter to zone 3.

edit: totally misread the question!

In Southern Minnesota z4, I planted bare root roses mid April. I bet now would be good for z3.

If you are willing to do the, "rose shuffle," moving potted roses in during the frequent spring frosts and back outside on good days, you have a much bigger selection of roses than buying locally, especially from the big box stores. Finally, after all danger of frosts is passed, into the ground they go. So you buy your zone 3 winter hardy roses on line, when their availability is abundant, and do the rose shuffle until the frosts are past, then plant them.

Wish there were more roses you can grow but the hybrid rugosas are ideal for you. Give Snow Carpet, aka. Schneekoppe, a look at.

Moses

I'm not sure just when you should plant Morden Sunrise, but it's cold hardy to zone 3 and 7500 feet altitude. I've grown it for years in a warmer zone, and love this rose, developed in Canada. Diane

I love Snow Pavement too, Moses.