A few points to consider
1) I'm assuming with bigger tank you will get more fish. Would you need bigger equipments to handle the bigger bioload? If so, can your smaller sump fit the bigger equipment?
2) do you use your sump as a refugium? If so, it will be less effective because it will be harder to compete against the algae in the DT bc now relatively speaking it will have a smaller surface area for light and photosynthesis.
3) do you have an ATO? If not you will have a more frequent top off cadence bc larger tank = more evaporation so the water level in your current return chamber will drop faster.