VaughanX: No Mods - just five men straight out of the box, as it were.
I finally got through it. You have to find a bridgehead, where you can funnel the enemy through (other than a pesky sniper who was outside shooting through the windows.) I found that running out of the initial room into the dining area, and then to the right, was the best. From there you just have to take your time, and let the enemy come to you.
Once most of the enemy were dead, I could explore at my leisure. This was a very difficult mission for me, I played this single mission over three days! But I did get through it without losing anyone. I found it take a good solid strategy to win - rushing in all guns blazing is suicide (not that it stopped me doing just that five or six times!) :D
In general rushing in guns blazing is a bad tactic. A little forethought, strategy, scouting, having soldiers cover each other... this all helps. Even when you seem to be overwhelmed, picking the biggest threats as targets (heaviest guns/snipers, depending) is a big help.
EDIT: That said, sometimes it's a real bit of fun to save the game, then toss caution to the wind and blaze away.
