I assume since you are an experienced solo expedition-style off-roader, you have the proper recovery gear, tools, spare parts and fluids stored securely in your rig to deal with most trail disasters. But for the benefit of any novices who come across this thread:

Recovery Gear

• Frame-tied recovery points (tow hooks, rings or d-shackle tabs)
• Quality Winch or Come-Along, 2X capacity of your loaded vehicle
• Winch extension cable/rope (can also be used to replace broken primary line)
• Winch line safety weight (can use a heavy blanket, towel or jacket)
• Snatch block, 2x tree saver straps, 3x 3/4", 4.75+ ton WLL d-shackles
• Full-size shovel (not a cheap folding shovel)
• 20"+ folding bow saw (or 12"+ chain saw)
• Hi-Lift Jack or similar farm jack
• Jack platform for use in loose soil/sand/snow (12"x12"x3/4" plywood works)
• Sand ladders (if appropriate)
• Leather work gloves
• Two fire extinguishers: a 2.5-pound unit mounted within driver's reach (outside of seat bracket is a good place) and 5-pound unit mounted in the rear. Use secure metal retaining brackets or quick-release brackets.

Spare Parts and Fluids

• 1x Gallon anti-freeze (concentrated, not pre-mixed)
• 5x Quarts engine oil (can run 1 quart low in an emergency)
• 7x Quarts transmission oil (trans, transfer case, power steering)
• 2x Quarts gear oil (differentials)
• 1x Quart brake fluid
• 5x Gallons (minimum) potable water (in addition to appropriate drinking supply)
• 2x Plastic clips for JK transfer-case linkage
• 12x Plastic JK fender clips
• Serpentine Belt
• Upper and lower radiator hoses
• 2x Wheel studs and lug nuts
• 2x Brake caliper bolts
• Drive shaft U-Joint
• Axle shaft U-Joint
• Minimum 12-feet each of 18, 14, 12 and 10-AWG insulated, stranded wire.
• Spare air hose and connectors if using air lockers
• 2-feet each 3/16" and 3/8" high pressure hose
• Assorted crimp-on electrical connectors
• Assorted heat-shrink, adhesive-lined tubing
• Assorted wire zip-ties
• Spare headlight, turn/brake-light, and aux light bulbs
• Spare fuses
• Assorted pipe clamps
• 2x 3" exhaust pipe clamps
• Assorted screws, bolts and nuts
• 6x spark plugs
• 2x Spare valve stems and cores
• Super-Seal Emergency Repair Tape
• Duct Tape
• JB Weld
• RTV gasket/sealant
  
  Now we get to the big items, which you need to decide risk vs. cost/weight
• Front and rear drive shafts
• Front inner- and outer- axle shafts
• Rear axle shaft
• Water pump
• Starter
• Alternator
• Engine cooling fan

Tools

• Tire repair kit
• High-output air compressor, on-board air or CO2 system
• Tire pressure gauge
• Tire deflators
• Screwdrivers (1/8", 3/16" 1/4" slotted, P0, P1, P2 phillips, T10, T15 Torx)
• Replaceable-bit Screwdriver handle w/bits (slotted, phillips, torx, nutdriver)
• Combination wrench set, Metric, with added 13mm, 18mm and 21mm
• 3/8-drive ratchet w/SAE & Metric sockets
• 3/8-drive 10mm, 16mm & 19mm deep-well sockets
• 3/-drive 3" and 6" extensions
• 1/2-drive torque wrench
• 1/2-drive extending breaker bar
• 1/2-drive sockets in 3/4" deep-wall and 35mm
• 1/2-drive 3" extension
• 10" adjustable wrench
• 10" channel-lock pliers
• 10" vise grips
• 6" long-nose vise grips
• wire cutters
• electrical crimping/stripping pliers
• 14" pipe wrench
• 14" pry bar
• Large C-Clamp
• Magnetic parts retriever
• Leatherman Surge multi-tool
• Hand axe (can be used as a hammer)
• Jumper cables
• Welding rods & goggles (if you have dual-batteries)
• Butane Soldering iron, solder & fuel
• Measuring tape
• Blue Loc-Tite
• Safety goggles
• Nitrile shop gloves
• Gortex/suede shop gloves
• Zip-Lock bags (fluid/parts storage)
• Trash bags
• 5'x9' poly tarp