If you haven't moved yet, you should try to wait until you secure an apartment in your new city if possible. Different apartments have different restrictions on size or breed. It always depends on the building, but it could be something like a 30 lb or 40 lb limit. Also, if you find the apartment first, you could get a dog that fits the apartment. So if you find a space with a yard or park nearby, that could open up some options for you. Or, you might end up needing to live with roommates at first when you move to a new city, in which case, not having a dog might allow you to find a better, cheaper place.

Of the breeds you like, you're right, a landlord or owner would probably be more likely to rent an apartment to someone with a collie rather than a GSD or doberman.