Yes - you can use an IGH with multiple chainrings, but there must be an effective way to take up the slack, which means a chain tensioner. But should you?
A Shimano Alfine 11 has 11 gears and a range of ~400%. The Rolhoff has a range of 500% over 14 gears. So changing chainring will give even more range - question is whether its in a useful part of the gearing.
I ran the alfine11 on a triple chainset, and I never ever needed the grannie gear, not even going up the steepest hills. I did use the middle occasionally, but it was very hard to change when doing sub-5 km/h speeds. In the end I just stayed in the big chainring on the 15% grade.
Tube changes are totally possible with an IGH - depending on how its controlled you may have a power cable to unplug, an inner cable to unhook, or maybe nothing if it has an internal battery and Di2 wireless control.
I ran an IGH in some short dropouts fine - they come with antirotation washers that sit into the dropout. Upshot you require dropouts to be long enough for the axle and about the same again for the washer's tab. Ideally the dropout would be parallel, mine was "pacman mouthed" and that caused problems if it weren't tightened enough. So I added a 15mm spanner to the kit and all was well.
Most shimano IGH need an oil change yearly or every 5000 km. Rohloff is a little longer from memory. So there is still maint to be done, but its a cleaner system overall than a derailleur.
Do note that most IGH leak oil a little, specially when parked. So consider what's underneath.
Shifting while stopped is a neat party trick of the IGH, something the derailleur can't do, and very handy if you fast-stop at a red light with no chance to change gear.
You might consider waxxing your chain instead of oiling it. There's some equipment needed, and its a messy process, but the chain remains much cleaner over time.
For touring, a 3 speed IGH will lack the range. Most of them are plus-minus 33% and that's a large jump in gearing. You're looking at 7/8 gears in a Nexus, or 11 gears in an Alfine, or 14 gears in the Rolhoff Speedhub.
Finally, any IGH will require a rear wheel rebuild. They're all wider than any normal hub, so you will need spokes of appropriate length. Its not impossible, but its not simple either.
I think your next ride, wipe down the chain every day after arriving at camp, and give it some chain lube daily. That alone will help you. Give the chain a deep clean about a week before you set out.