This is a problem I face when I’m traveling; it can also be applied to not having any money for the gym, but it always affects me when I travel.
I’ll get to the hotel and all they have is a broken treadmill and one 5 pound dumbbell.

My workout schedule while traveling is broken into legs and obliques on the first day and chest, back, and core the second. I have it broken down like this because I usually find a gym by the second or third day.

4 sets of air squats, 10 reps each

4 sets of lunges, 10 reps each

4 sets of calf raises, 10 reps each

4 sets of Russian twists, 20 reps each

4 sets of bicycle crunches, 10 reps each

All of these are done without a weight.

The second day is simpler but more physically challenging.

4 sets pushups, 25 sets each

(It doesn’t seem like much but this will smoke you)
4 sets of crunches, 15 sets each

4 sets flutter kicks, 15 sets each

4 sets planks, hold for 15 seconds each.

If the hotel has a treadmill that works I will walk on it for at least 15 minuets.