Definitely worth it. You won’t gain, but for the most part, you’ll maintain.
If you can swing it - consider adding in a simple bodyweight movement day at home too. Light weight (or no weight, depending on what you have), just focus on mobility, going through all of the motions, and activating all the muscles.
That’s what I do in the winter and I see improvements - October to April then in the summer I race TT and do planks/press ups 3x week. I found my hex bar deadlift went from 60kg to 110kg over the winter…not big numbers (although I only weigh 61kg) but certainly an improvement…I do a 2 hour session though Sunday morning with 45 mins of treadmill running in there and then a short 45min V02/threshold TR ride in the evening to add to the er…pain!
If once a week is all you can do, do it. It’s infinitely better than zero times per week.
You should consider taking some exercises to actual failure in the 6-12 rep range (meaning use enough weight that failure occurs in that range) since you have a full week of recovery ahead - think machine-based ones like leg press, machine bench, machine military press, lat pull. Actual failure is just that - you cannot complete the last rep despite giving it maximum effort. A way to progress with this would be go to failure with maximal weight for 6 reps (i.e. you fail on rep 6). Stick with this weight and, over time, increase the reps, so failure occurs on rep 7, then 8, then 9, all the way until you are able to actually complete 12 reps. Increase the weight and go back to failing on rep 6.
To incorporate this into your routine, do the routine you mentioned in your post. After completing it, do 1 set of leg curls to failure, 1 set of machine bench press to failure, 1 set of leg press to failure, 1 set of lat pulls to failure, 1 set of calf raises to failure, 1 set of machine military press to failure.
Unless you have training partners who know what they are doing, do not go to failure using exercises like the squat, dead-lift, etc. it’s not worth the risk of injury, especially to your back.
Sort of. TomW86 mentioned a routine that involves squats and deadlifts, which are risky to take to failure, as well as some bodyweight exercises, which involve mostly metabolic efforts. Leg press, leg curl, bench press, military press, and lat pull can be done with heavy weights that initially result in failure by rep 6. He could go 100% Mike Mentzer with his routine but I personally think it’s good to incorporate volume.