Literally in the country?
Make your own sandbags and use them for farmer's walks, 100 squat challenge. swings, skull crushers, weighted lunges. 25, 50,80lbs increments.
Look up boot camp workouts
one armed pushups. then add a ball.
100 burpee/squat thrust challenge
100 pullup challenge
Anything that is typical HS, boot camp PT and add that extra challenge to failure or timed.
Prison or bench dips.
Make some markers and sprint repeatedly
If terrain is rolling then carry those weights up/down hill
Loads of stuff that will harden you up.
Maybe you can bring a 50lb 2" battle rope? Or a TRX setup? Although the above is enough as you can do many derivatives of body weight or body weight plus what you can make/scrounge.
And if you are doing outside physical labor that will be punishing enough and you will be focused on food and rest.