well I roughly counted my reading time of the latest comic (8 seconds), now Freefall updates monday wesnesday and friday, so three times a week. the first strip was published 1998, 22 years ago.
there are 52 weeks in a year.
52 x 3= 156 comics a year
156 x 22 = 3432 comics, approx.
3432 x 8 = 27456 seconds
27456 divided by 60 = 457.6 minutes
divide by 60 again and you get approximately 7.62 hours to read Freefall in one sitting, though its understandable if one takes breaks and wants to spread it out a bit.
its not exact, but this is a good rough estimate of how long it would take, not taking into account months and such.