I can now confirm that the event map can be completely cleared with a brand new lvl 50 commander, which is the absolute highest commander gap anyone is going to see, unless you hosed yourself by using two different platoons. This event is totally doable. If you can't get past a tile, you need to examine how you're approaching it and try something different.

Also, more than enough jingle bells are available to make up the difference if for some reason you still can't clear tile 8. This is day 3 of 21. You need to collect 13,887 jingle bells by the end of this game day to supplement clearing only 7 tiles on each path of the event map (day 21's total is approximately 97,200). I've been able to get to 14,345 total today and there's still over half of the day left. Send Light scouts out for oil. Spend oil on PoC, invasion tiles, and farming your highest no-repair tile...personally, I've moved on from Nethercold Sea to Under the Ice for better jingle bell rewards.

There is no whaling required for this event if all you want are three copies of each of the main event tanks. Seriously, people...do the math. Chart out your total jingle bells required each day based on how many event tiles you can clear, then go farm them. It's not that complicated, but it does require more oil than just your rigs. If your 5 scouts can bring back about 200 oil each, that should be plenty.