I grow a number of roses that show less than 5% BS (Morning Magic, Brite Eyes, Walking on Sunshine, and Thrive! to name a few) but the healthiest rose that shows NO sign of disease is ‘Snow Carpet’, which is New Penny × Temple Bells. Not only does it show no sign of disease it also sets OP hips and also has some descendants listed on HMF. It’s listed as hardy to zone 5b. I’ve had this one for two seasons but haven’t used it in breeding yet but will be using this one next season heavily. This winter I’ll see what shows up with the OP hips. I grow it in a hanging pot and let the canes hang down. I highly recommend this one.