No advice from this novice gardener but your idea sounds great.

-- a girl named "Max"

the typical standbys are boxwood and yew. There are several varieties that do well in MN; rather than bore you with listings of varieties, check out the local garden centers when spring comes.

Alternatively, any plant that could be used as a clipped hedge would work...alpine currant comes to mind.

I can envision a smaller topiary of sedums, hens & chicks.

I ended up taking the deer back and finding a place to buy the frames online at a better price than previous ones. It is an 18" poodle (I have two of the live kind).
It is small enough that I will probably use sedum hen and chicks.

A poodle topiary sounds cute. I'm keeping my eyes open for something different and small to use.

The poodle still isn't here. It shipped yesterday.

The poodle is perfect.

Great, I look forward to seeing it filled and growing.

Me too.