1-2 hours a month. I recommend you fly more regularly than this!
One advantage of Aeros is that you can do a lot in a short flight, in 20 minutes airborne you can take off, climb to height, fly a couple of sequences then back to land and in that you will have done more handling than someone who flies a three hour flight into France, so if you can only fly a limited number of hours this will be far more worthwhile.