once a year is my standard on my wife's car. [1994 chrysler concorde] she only drives maybe 6-800 miles in a year. this year who knows, as there is nothing open.......
the only thing to consider is, do you change in the spring or fall [before storage] ? there are differing thoughts on either. sometimes i do spring, sometimes i do fall. one thing i did at the begining, was to install a much bigger oil filter than the factory issue tiny one. there was lots of room once installed, but it is a little tricky to get on and off, both times filled with oil.
as trips are short, condensation is an issue. however, everything gets warmed up good because she won't go out in it unless it's nice and warm outside.
this has worked well for us since i bought it for her 19 years ago.
just my opinion. your mileage will vary.