Mom went into long-term care. The house is going to be sold and I live out of state. What's the best thing to do with the mail?

Do I get a post office box in the state she is in or just have mail forwarded to me out of state? I didn't want someone like Medi-Cal or Social Security to think she moved out of state and didn't want to affect her benefits. But need to know what is the best thing to do with mail. I have family that can pick up from a P.O. box and send the mail to me. I'm the one that has power of attorney.