If you go with 24v panels(high voltage) you will need a more expensive MPPT controller.
24v panels are about 200 to 250 watts each.
1 panel, Morninstar sunsaver 15a MPPT
2 panels, Rogue 30a
3 panels, Morningstar Tristar MPPT 45a
4 panels, Morningstar Tristar MPPT 60a
Trouble is they get expensive so the best value is to max it out. Then there is no room for expansion. Probably the single panel is plenty for most usage. Especially if you have an on-board generator when needed.
A few are looking at the Eco-Worthy 20a MPPT controller as a lower cost option from China.
Otherwise the Rogue might be the best option to go one more panel in the future.