A March in the Snow, Part 1 is the first part of the seventh chapter of Valkyria Chronicles 4. The combat mission in this is Mountainous Retreat.
Claude, I've got a situation report for you
"Our orders are to outrun the Imperials and make it through the mountains. There's a clearing north of here, so let's get there first and get into formation. The enemy's closing in from behind, so there's no time to lose. We won't be able to set up camp, either. Don't count on getting reinforcements. Hate to say it, but we're still catching our breath from the last retreat. If we lose too many troops, morale will drop so low we may never recover. We need to clear every obstacle in our way to make sure that doesn't happen. And I'm sure this terrain has some good sniping spots, if you know where to look."
Location: Achtzehn Mountain Trail
Description: Get 3 units to the target while fending off pursuit. The countdown from critical condition to death/retreat is reduced by 1 turn. Do not lose more than 3 units.
"We're going to get through this. Together."
One possible strategy to make this mission easier is to use the Cactus to transport your units to the target area -- with the Cactus' resistance to small-arms interception fire, it allows your units to much more efficiently move (and with less CP) to the target area than on their own.
The only wrinkle to this tactic are the Anti-Tank Cannons guarding the bridge before the final destination -- they are capable of badly damaging the Cactus and forcing it and the units inside to retreat. This makes destroying the cannons a high priority.
Imperial reinforcements arrive every turn at the player's starting point.
If any enemy leaders, tanks, or stationary guns are destroyed by an avalanche, it will not be credited in the mission report.
Although it seems somewhat silly for military leadership to place Anti-Tank guns right in active avalanche zones, there actually is a good reason: Avalanche Control. Real-world park rangers use a variety of techniques to alleviate or prevent the damage avalanches can cause, ranging from building avalanche barriers, reforesting bare mountains, and using explosives to trigger smaller, less destructive avalanches.The U.S. National Park Service and Forest Services even use spare military artillery to preemptively triggers these mini-avalanches; a possible in-universe explanation for these AT-Guns and grenadiers is that they are avalanche control cannons repurposed for wartime.