Not sure what your gym program and goals are, but 30 mins at a time can already achieve a lot if you go enough times per week. I usually just lift, and after 30 mins I'm out of energy so that any subsequent lifts would be weak and technically poor anyway.

Yeah mostly lift - but i've recently started doing cardio more seriously and it does become daunting sometimes to commit to 90 minute endurance session etc - but I often remind myself it's the difference between something and nothing.