Hi Paul!
Are you "Jussy" Paul, by the way? I ask this, because you sound exactly like a buddy of mine from my area who is named "Paul," is around this age, has kids, and is a scientist. If you are not him, all I can say is: WOW...What a coincidence!
Anyway, the response from Deltadiscos outlines a similar approach that I have actually used. Although I recently left my 9-5 "career" in order to focus more on my music, and I do not have any kids, I was able to keep my chops up and also continue learning new things while balancing everything out with my career and marriage (it definitely helps that my wife is a musician, too).
My schedule began around 4:30 A.M., and I tried to keep this as consistent as possible Monday - Friday. That was my time; chiseled out each day, dedicated to practicing and/or playing music.
Based on my experience, one of the most important things to remember is to make time to actually PLAY guitar, not just "practice" guitar. Even if I only had 15-20 minutes, I found it better to throw on an extended backing track (these are all over YouTube) and just play. Sure, I got my practice time in, but I made sure to take time throughout the week for playing along to backing tracks in order to apply that which I was learning. Not only did this keep guitar playing interesting and fun, but it also exposed areas in my playing that needed improvement. Eventually, you will most likely discover the same and can drill the more challenging items on the Daily Practice Routine.
MOST IMPORTANT = PLAY A LITTLE EACH DAY!!!