Great preparation for kidding. Always better to be ready instead of running around trying to gather supplies at last minute! LOL Might not need the lamb coats unless the temps plummet. However, since you have wool sheep, the mamas will go about their business outside while the lambs shiver. Make sure the lamb coats are waterproof if the ewes have access to wet weather. You can spray them with waterproofing spray yourself. If the lambs are tiny, large stretched out men's socks can be used for the first week or so. Cut hole for head in toe portion with holes for forelegs. Leave butt end open for peeing and pooping. Used this for a set of premature quad Nubian goat kids born almost hairless. All survived and 2 does went on to be show winners.
I went to school Kylemore Abbey 50 miles into the Connemara countryside, Ireland, and in spring the sheep would lamb on the hills (free range). Lots of white dots on green hills were lambs that had died from cold temps or rain.
Early last century in Utah, spring shearing was finished and the lambs were born when a freak freeze and blizzard came through. Most of the flocks froze to death. Horrible to see when the snow melted. Devastating for those ranchers.