Talked to Rivian today...they are aware of the issue. I really like your idea of traveling with a spare tie rod or two. Rivian service is going to get back in touch with me with how I can procure a couple from either them or the supplier that made them. They are not currently planning on changing the tie rods they use. I am sure the after market will eventually offer something that is appropriate for off roading in a Rivian.
It is common to carry extra parts when off roading. Like mentioned im a Land Cruiser guy, very stout and reliable. I carry JB weld, duct tape, baling wire, there are quite a few regular trips I make that I take an extra spare tire (so 2 in total): Dalton highway, stease highway, dempster highway, McCarthy road,…. Jeep guys I off road with carry: axles, u joints, drivelines, synchros, steering pumps, …. Land Rover guys take a back up toyota, tow truck, or sat phone, flair gun, and supplies to survive while they are waiting to get rescued
in the grand scheme like I said tie rods are relatively easy and cheep to replace on trial. Personally I would hate to put on beefier rods then blow the air spring, control arm, driveline, CV,…. I would add that make sure you have the tools needed and a hi lift Jack that will work with the Rivian.