Typically, zone 8 is listed as the coldest zone in which Cortaderia selloana 'Rosea' is hardy.

Will deer eat pampas grass? I have a deer problem and don't want to plant the grasses if all of it will be eaten by summer's end! Is there a suggestion to keep the deer from eating it if they DO eat it?

These grasses are said to be deer resistant:

Inland sea oats (Chasmanthium latifolium)
Maiden Grass (Miscanthus sinensis)
Gulf Muhley (Muhlenbergia capillaris)
Lindheimer's Muhley (Muhlenbergia lindheimeri)
Pampas Grass(Cortaderia selloana)
Purple Fountain Grass (Pennisetum setaceum)

That said, if their only option is starving, they'll eat any plant they can get.