When I've wanted to carry more gear than I want to carry on my back or shoulders, I use one of these .
I've also toured around with the bike and trailer with camping gear as well.
Solar chargers for phone and camera batteries where necessary.
Topping up the bike battery in pubs , cafés or campsites overnight.
Although I usually tour in a 1985 VW campervan, so have more gear with me then!
The handle on the four wheel cart can be separated and can be connected to a small towing vehicle, a ride on mower or mobility scooter etc .
I've also had that fastened to a bracket on the panier rack .
I bought a nice fold up wagon with big off road type wheels. While it did the job is was quite large and somewhat heavier than I desired. it is now happily trundling my friend's kids and accoutrements...
Now that I put the big heavy Graflex camera on the shelf and have the much lighter Nagaoka 4X5 that fits comfortably in a medium padded backpack (including 4 lenses and a meter) I can carry it easily without any cart if desired. If going sans cart, I con my assistant (wife) into carrying the tripod. The 'pod is an olde Bogen 3021 set of legs with a nice Manfrotto X Pro ball head. The combination is reasonably light and sturdy enough to support the light 4X5. My big Bogen 3068 legs with an equally heavy Bogen 3055 ball head sits in the corner waiting for a big camera...