If you are here (or anywhere overseas) long term, I recommend a mail forwarding service. Personally I use Traveling Mailbox and its been great, but there are many registered commercial mail services. I use it with Schwab as my mailing and then have them forward it on. Has saved lots of headaches over the years. Alternatively, as others have mentioned, I would probably just give them a call and say you are overseas for 3 months and need a new card etc. They will likely send it.
As for the phone, I transferred my verizon number to google voice for like a 25 dollar one time fee, and now have google voice with a real US number, free forever. Works with with Schwab and Chase and most credit card companies in terms of getting codes etc. Difficult to set-up while overseas, but worthwhile on a trip back.