Only had one single axle TT. Loved it...but it was SMALL for 2 of us and crowded for 4. The one item you mention about a flat tire/blowout on single axle is a big safety factor in two axle trailers.
Not knowing your full situation, if it was me, I'd keep the TT you have for (1) size/room/safety, (2) as wanderinggaimlessly said, to do the occasional trip with your teen, (3) for the fact that prices are nuts and might be best to keep what you have.
I guess for me it might make sense to do a 'steady as she goes' approach and do nothing, which is always an option!
