Instead of taking up 5 rows, why not call in after you make the res and have them open up some B seats for two of you and keep the last one in a lone A seat? Then you would only be blocking 3 rows and they would probably be less inclined to move you in advance that way. That's what we do when traveling together right now, including when they were blocking F aisle seats. We would call and they would manually seat us beside each other. It gives you the seating you want as well as not tying up full rows since it seems this is what you do at the airport anyway. This way, it opens up rows so other people can buy them in advance rather than you tying them up until T-2hrs or so. AS is already losing money by seat blocking so why not let them sell a few more seats in advance if they can and you still end up with the seats you actually want anyway.