I've always reported mine lost. Gives you the same options and you can start back up . As somebody else mentioned wait till renewal bait if you're downsizing or even if you're upsizing because you pay the new price I don't believe you pay the differe...
I have gone down to a cheaper plan and then back up. Sometimes that's plan is no longer available but they always had great plans so I didn't find it a problem only that the dollar reward stopped