I wouldn't worry about it too much. A year/10 months is still a decent amount of time to be involved in an activity. As you mentioned, I would still look for new opportunities just so you don't stop EC's completely - I feel this would be more likely to raise a flag rather than simply switching activities due to location.
I am relocating cities a year before my first application cycle and therefore will have to stop my current EC's and look for new opportunities (volunteering/researcb etc). The commute to my current ECs is far and not feasible w/my class schedule. How bad will it look that my recent activities would have only been done for a year/10 months come application time?