Bonni and Bob Gumport travel regularly in their retirement. Not beholden to one short holiday a year (they average seven big ones), their compounding experience has allowed them to develop a code of rules by which they abide – tips and tricks to use wherever they go. After one too many of the small rooms common in boutique hotels, for example, they’ve cut them out entirely. Also out of the question are walking tours within two days of arrival in a new destination, as they prefer to…