I'll still do large venues, but the seats have to be in a spot I can clearly see the stage. So lawn seats are a no. Another thing I do, buy cheap seats, then the day of the concert, a couple hours before it starts, ,look on TM or LN to see what seats have not sold closer to the stage. Then go sit there. I'll look for a row with several open seats, on the chance that no one is going to buy a last minute ticket for that row/section.
I wonder if you would be allowed to carry one of these in...
Amazon.com: 2022 Upgraded Retractable Folding Stool