Honestly I usually just jump back in where I left off. Longer periods of inactivity, I will manually adjust my FTP down an appropriate amount. Maybe 10 watts for one week and gradually increase it over the next week or so.
I follow a low volume plan and will stack the workout hard for the holidays. All three hard workouts for the week in a row if needed. You have to be smart about it though. Usually do the VO2, then threshold, then sweet spot. Basically use the intensity factor to determine workout order. If I can do that, everything else is bonus. I’ll try and get a 30-45 workout in on a couple days later in the week, but the key workouts are done.