The only reason a lift would close due to snow is if all of the terrain accessed from that lift has a high avalanche danger. With only 1-3 inches forecasted, that shouldn't be a problem.
The real difficulty will be low visibility. Most of the terrain you'll be skiing on will be above tree line, which means that visibility will be poor when it's snowing or even when low clouds are passing through. Before you commit to the journey, you might want to do a quick test run on the Zermatt side to see if the lack of visibility causes you a problem.