Strength is relatively easy to maintain, and you lose it much more slowly than cardio. There have been a number of real studies (i.e. not bro science, but published peer reviewed stuff) that show that one near max session a week of low reps can maintain almost all of your current strength. Try one session a week, no longer than 30 minutes, of something along the lines of 3x3 in the important lifts (big muscle stuff like deadlifts, squats, press, etc). And then when you hit your running/endurance goals, you can shift to maintenance there, and focus back on strength. That is actually the best long term plan anyway for all of S&C.