Not sure how your permits are due to expire if you haven't picked them up yet. Clock starts as soon as you pick up and pay any outstanding fees. Bldg Dept is closed to public as of March 18, 2020. There's more info on their website: www.clarkcountynv.gov/building
Just pull out the permit and it will be good for 180 days without any inspections. And if it gets expired, you can renew it again for half the price. But with the current situation, you may have to just pay online and get the permit. And to actually get a physical approved paper plan set you may have to wait until the situation gets better and County starts to function normally.
Thanks! Your answer is awaiting moderation.