Keep in mind that without shore power the battery alone will only supply power to the 12V DC system, unless you have an inverter. If you plan to use only 12V items conservatively, IMO a fully charged 12V Marine/RV battery should last you through the weekend. If you are using an inverter to power some 120V appliances (toaster oven, etc.), then you may find the battery discharging rapidly.
The low watt (15W-30W) solar panels are good for maintaining a battery (or bank) charge while in storage, but they are not designed to keep up under daily camping battery use. A 100W to 300W solar system would be required to be of any real value for camping off the grid, then of course you need at least 5-6 hours of direct sunlight every day (1K-3K investment).
One option would be to consider upgrading to two batteries, or carry a fully charged spare. As a last resort, carry a pair of jumper cables so you can recharge the battery. Avoid letting the battery go completely dead, this will impact battery life and performance.
Hope this helps.
2016 GM 2500HD 6.0L/4.10
2005 Jayco Eagle 278FBS
Reese HP Dual Cam
Putnam Class V