Posted: 22/03/2014 at 06:40
Don't panic - I'd move the pot into a sheltered place outside - keep the soil damp but not wet and soggy. Hopefully by this time next year you'll have some healthy new growth. Don't worry about the current leaves yellowing - the reason is as Dave explains.
Don't worry about feeding until next spring.
As for whether it will come true to the original - the grafting only affects the vigour of growth, it will not affect the appearance of the flowers - you might find that your new roses are more vigorous than their parent.