It has gotten a lot easier due to the internet.
We have two accounts we set up with debit/ATM cards, where we leave 6 months worth of expense money. One is BofA, which has high fees, but offeres billpay services--we only use it when we are in the US, but it is a backup for our Fidelity acount, which has low fees and better interest. Both are separated from our major accounts, which have much more limited access to protect from fraud.
We now leave a beater car at my brother's with insurance, but have gone several years without a car. The insurance companies have let us come back at preferred driver rates when we showed we had been out of the country.
We have been using a family member to sort and send the mail, but they tend to burn out after a year or two...
We get prescription meds 3 months at a time, but sometimes it is a worry forwarding them to overseas addresses. So far, no problems
The family member who is taking care of our business gets a power of attorney and is listed on the BofA account.
We use Turbotax and online filing for the annual tax PITA. Much better now than when we had to trust an American tourist to take the returns back and drop them in the US mail.