Yes and no. First, durable powers of attorney are independent documents. The durable power of attorney you have for your spouse should not be part of the trust, though it might have been executed at the same time.
Second, the document should be honored in the new state pursuant to the full faith and credit clause of the U.S. Constitution.
But, third, the document is old; while this is not a legal issue, some banks and financial institutions are reluctant to honor older durable powers of attorney. In addition, many banks and financial institutions are simply more comfortable with in-state documents that are familiar to them.
So if your spouse is in the early stages of dementia and can still sign a newer, in-state durable power of attorney, that would be the best course of action.
Harry S. Margolis practices elder law, estate, and special needs planning in Boston and Wellesley, Massachusetts. He is the founder of ElderLawAnswers.com and answers consumer questions about estate planning issues here and at AskHarry.info.