This is advice I give everyone, and one that happens to have merit more often than you may think. There are a high number of software and application changes which occur on a regular basis. Given the desire of all companies to offer the latest features more often, coupled with continued scrutiny on cyber security and the need to patch gaps and flaws in software almost daily, something on your PC or Mac may need to be updated everyday. If you expand this to the IOS (iPhone and iPad) and Android worlds, something changing daily may actually be the norm (at least until some breakthroughs occur in the field of cyber security).
OK, so given this reality, and given a second reality, that most of us would be crippled if our PC or Mac or other device stopped functioning just before or during a critical business trip, the logic is sound: think twice before applying a change to something that is critical to you just before you might need to use it. Wait until a less crucial time, or insure testing of a change on another device. I was faced with this decision yesterday, as I was on the road, and I was starting up my VPN client (another critical road tool to insure privacy and security), a message popped up indicating the availability of a new version. At home or at the office, I may have just upgraded; but actually travelling and having limited ability to troubleshoot if something went wrong, I filed away a note to upgrade later and insured that my current capabilities were uninterrupted. This is sound advice for all but the most critical of security patches, and if you practice good and regular update discipline, should keep you functioning at the most critical times.