How to keep cream cheese for a long time?
The "best before" date is usually way out. Cut it in slices that you will use within a week. Still Tasty recommends that you use opened, refrigerated cream cheese within a couple of weeks. Very well packed (well wrapped or preferably vacuum packed) cream cheese really should last longer than that. I'd try for keeping a month's worth, refrigerated, in well wrapped packages that you won't open until the last one is gone. Freeze the rest. Frozen, it will lose some creaminess, but will still be good in cooked applications. Again, Still Tasty is a bit (IMO) overly conservative. They suggest (for quality only, not safety), keeping opened cream cheese in the freezer for only two months. I'd allow at least three, if not four. Of course it will stay safe in the freezer indefinitely. In the fridge, just watch for mold, toss the whole thing if it develops mold. You can't just cut off the moldy parts like you can on hard cheese.

EDIT: Just FYI, some places in the US that sell the 48 ounce brick also sell 50 count, 1 ounce packages. Quite a deal for less than $2 more, epecially if the sell-by date is well out. (This picture is from Sam's Club, but I think the other big warehouse store carries the small packs too.)