roast beef, how long does it normally last in the fridge?

[MummieHunnie]

I cooked it two days ago, we had leftovers yesterday, there is still loads left, I have cut it up into slices and left it in the fridge, I want to freeze some of it to use again later in Jan as it was a huge roast (1/2 price in supermarket), i have no room in freezer at moment, how long do you think before it is too late to freeze and how long can you keep it in the fridge?