My plan is to do two strength sessions per week for the first three (base) training blocks, gradually increasing the weight, and then back the frequency off to once a week maintenance once I start introducing greater amounts of supra-threshold intensity on the bike. At 53, I find I can work hard with weight or work hard on the bike, but both is pushing it.
Given the choice, I’d rather add a long ride than add a strength session, given that my short power is a relative strength and my endurance is a weakness.