soilsandup , Unless the rootstock is fresh which I kind of doubt the ones from Costco are, I doubt that they would make it, but maybe you would have some luck.
JuliaNY here is where I got the ones I had the best luck with so far.
sale 3 EREMURUS RUITER HYB CLEOPATRA 1x3 (3) for $5.25 Van Engelen
sale 5 Eremurus 'Orange Marmelade' $20.00 sale (5) for 10.00 large flowered and tall; dark orange and real 'traffic stopper'! 4'-5'. Brent and Becky