We used to head down to LV every easter for many years in the late 90's 2000's. If easter was earlier some years then we might hit a bit of snow around Cedar City to St George Utah, one year huge flakes and settling but just kept going real slow till came out of it in less than an hour. Then we were towing a 33ft fifth wheel with a Ford F350 Dually (dually's are not kind on snow or gravel!). All was well just knuckles white for a wee while. Be conscious in Montana around Prickly Pear and those many bends in real cold weather if going down I15, this side of Helena if I recall. Beautiful in the summer but treacherous in the winter if icy.
We will likely be doing what you are in the very near future, travelling in our MH down from DeWinton Alberta to AZ,NM,NV,TX as snowbirds in Januarys after spending Christmas with our family here. We will just check the farmers Almanac and weather forecast in deciding when to leave after Christmas, waiting as long as we have to, and if we hit concerning weather enroute will for sure stop and take some shelter with our Mr Buddy heater for as long as it takes. We never dewinterize until after we hit Mesquite, carrying canisters of water for strip washes/cooking the first two nights we are on the road.
We wouldn't leave until weather forecast is favourable for at least a couple of days, and get as far south as we can safely. We usually leave around lunch time one day and by late afternoon the next day we are in Mesquite or Zion depending on the plan.
