This cultivar is listed as triploid in the paper 'Pollen diameter and guard cell length as predictors of ploidy in diverse rose cultivars, species, and breeding lines'
NW Ont, Canada, USDA Zone 2, I had Nearly Wild for four years, it bloomed continuously, no winter protection, some winter kill, but would come back beautifully after spring pruning. I found that this rose did not like to be dry. Disease free, (if I noticed any leaves turning yellow, I would remove the whole stem immediately). Size stayed at about 18" H, x 2' W. Nearly Wild finally died after 2 years of competition with weeds due to total neglect (because of personal health problems) but is on my list to plant again because I enjoyed it so much.