Have a Trimetric or similar digital charge monitor installed so you have an accurate picture of the state of your batteries at the start and what they are in the morning and how long it takes to recharge them and to what degree they get recharged when driving. Otherwise you are in the dark as the displays provided by most RV manufacturers are virtually worthless.
Once you know how much you are using you can make an informed decision as to whether to add more charging or more storage capacity. Usually it is cheaper for trips of 4 days or less to add another battery than to invest in a generator or solar charging setup.