In campground winterizing

[sande005]

Not new to this at all, but a very late fall trip has me thinking...
I prefer, for storage here in Minnesota, to blow out all the lines with air first, and then add antifreeze. It is not uncommon for us to get snow/freezing weather by Halloween. Last year we made a return trip just before that date, and at the last campground before home, I winterized just with antifreeze. Doable, but not fun when the morning temp was 38 degrees. I was a bit nervous over the winter, but spring revealed no issues.
This year we will be returning mid-November. I'll keep an eye on the weather for the trip, and winterize in a better climate CG. Then motel it for the last night or two home. (Almost all northern locations for camping will be closed by then).
So, 'tis impractical to lug along my main bigger air compressor. I have a small Harbor Freight 12v I use for tires, etc. on the road. Would one of the smallish portable tanks (again, Harbor Freight) have enough capacity to do a decent job of blowing out the lines? Fill it using the small compressor, then use it for the job.
Or am I overthinking it, and just doing a good job of draining and using -75 antifreeze good enough?

(For those in less northern climes, it is not uncommon to get streaks of -15 to -30 below over the winter...hence the preferred belt and suspenders!)