Back of the napkin I would figure 100 watts for an hour per day or 100 watt hours per day.
An 85 amp-hr (standard automotive size) battery holds 85 x 12 or 1000 watt-hrs. Use the 50% discharge rule of thumb for lead acid deep cycle batteries so an 85 amp-hr battery has 500 useable watt-hrs.
Design for three days without sun. 300 watt-hrs might be a good number.
An 80 watt panel will provide 80x5 or 400 watt-hrs per day in five hours of sun. There are inefficiencies so 300 watt-hrs from the 80 watt panel might be a good guess.
You will need a charge controller so you don't overcharge the battery.
For a first look I would use an 85 amp-hr battery with an 80 watt panel and a controller.
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