You should ask about this on their forums, as you'd get people that have been throught the process already. They do cross-ship for some, but they might require a deposit. I havn't been though evgas rma process, but I think it should be around 2 weeks. I read somewhere that they get it out in and out the door in 3 days, then shipping both ways, so figure 13 days with 3-5 day ground shipping both ways.
Really though ask about it in their forums, you'll get accurate answers from a dozen people that have been though this. Here the most you'll get is 2 or 3.