Well I guess I'll have to answer my own Question. I've cut two Rugosa roses to the ground last spring. The one with the lower cut 1 foot is definitely doing better than the one I left at 2 to 2 and half foot. That being said we had a very very very cold winter. So who knows, thanks for all your input.

I just saw your post and curious what made you prune so severely in the first place - wanting to control the overall size or was it damage of some kind? And I'm not sure I understand you as you say you cut them "to the ground" but then mention one being 2-1/2 ft. I'm guessing you just pruned low, but didn't remove canes entirely. Generally, rugosas do not need regular pruning other than to remove entirely one or two of the oldest canes (3 yrs or older) every spring to encourage the plant to push new growth. IME rugosas do better with the cane being entirely removed at the ground (literally) rather than shortened. Shortened canes never came back to bloom as well for me as a cane allowed to reach full height and not touched by pruners. YMMV.
Anne

The rose was almost 20yrs. old, its huge eating up my back corner, big decline in rose production. So I decided to try and rejuvenate the bush. I did jens Munk and Henry Hudson..