Doing a google search on remontant hydrangeas, brought me to this thread. I own 'Wedding Gown' & 'Pistachio' or 'Glam Rock' as its known across the pond. Both hydrangeas do not get huge figure about 3' X 3'. 'Wedding Gown' I have noticed, in our zone 7 winters w/o protection dies almost to the ground and emerges with new growth in spring. The plant blooms on new wood. I have not encountered 'die to the ground' with 'Pistachio'. Both are well behaved in a Northern exposure and a Western exposure in the shadow of a magnolia.

S&C is patented under the name 'Jon01'. It was discovered in the Netherlands in 2001 as a naturally occurring mutation of 'Taube'. The distinction of Jon01 is it's reddish hues (hence the commercial name it's sold under as a gift plant). Taube supposedly grows to 5x5', so I'd assume this plant is capable of the same. Here is a link that might be useful: Hydrangea macrophylla 'Jon01'

I have a couple of these plants from soonerplantfarm...when I got them in April, they were a single twig (about 5 inches tall) with two leaves...I thought, gee, that will take forever...but I was wrong...this plant is very much like Annabelle, very fast growing once it get going...my baby plants are now the typical size of the endless summer you get in a 2 gallon pot - about 18 inches high, 12 inches wide, with 10-15 pairs of very large leaves..the tender twig has now woodened and very woody, and sturdy...the leaves are large..some of the plants have developed flower buds, the buds look large than considering the age of the plants...as I always do with 1st yr plants, I pinched the flower buds off and the plants are growing and branching quickly..I think this plant will be pretty large in maturity..and considering they came from single twigs and able to develop flower buds this quickly, likely a strong bloomer as well...the twig hardens significantly...I gave the plants some vertical support with stakes back in May, early June, when they started to put out more leaves and we had a couple of violent thunderstorms...now, staking is probably not needed...the plants takes whole morning sun (8 am to 12 pm) then filtered shade till 4-5 pm, then the sunset sun again till sundown...no wilting of leaves..so things are moving along quickly with this plant...someone said they get the finished size plants (2-3 gallon pots) in some markets, I am not seeing those here in Jersey..every commercial grower I checked have said this plant is in short supply and have lots of inquiries..these growers suggest there maybe some better sized plants be on the mkt later this season (maybe all the single twigs are now fully grown..hehe), and most definitely in 2010 season..

Mine is still small but for a year 3 it has a lot of flowers. People have commented on it's arching habit and it's been suggested a raised 'bed' would give it the height it needs so the branches don't drag on the ground. I planted mine on top of a retaining wall that is 4 feet off the ground with that in mind. It's branches are already arching down significantly