I will answer this with questions... if you bought a freezer, what will do with the fridge? Probably sell it.
If you get rid of the fridge, where will your hops be stored? In the keezer on the hump section
If you plan on keeping The fridge, what will you use the fridge side for? I will keep 4 kegs in that and the extra 2 kegs in the new kegerator but will have to run both fridges
Do you have power? Ie... is the Fridge on its own circuit or is it shared with other items? Is it a 15 amp or 20 amp circuit? Or do you have another circuit close by to attach a freezer too? Their is a double power point where the existing kegerator plugs in. I think a freezer next to it wont draw too much extra power anyway.
I miss having a small freezer,just to keep my hops and ice in. My fridge died so I went to a small freezer. I use our up right freezer to store my hops in ( so limited space) and buy ice the day before I brew.