Most hotels have a fitness room equipped with some dumbbells and cardio equipment. Sometimes the picking is slim. The following workouts are for spots with very limited equipment.

12 Minutes of lunging
Every minute on the minute:
5 (Pick one or a combination of:  Burpee, jump squats, pushups, dips)
(reps can be above 5)

Sit Up Cindy
20 min, 10 min, or 5 min AMRAP
5 Push ups
10 Air Squats
15 sit ups

4 rounds:
36 second plank hold
24 mountain climbers
12 second Handstand hold
24 mountain climbers

4 rounds:
10 glute bridge
5 single leg glute bridge R
5 single leg glute bridge L
400 m run

4 rounds:
1 min front plank
rest :45
1 min reverse plank
rest :45
:30 side plank
rest :20 seconds
:30 side plank
rest :20 seconds

These are just a few ideas. If there is equipment, a pool, an ocean, mountain trails; adjust these to accommodate. This is just the to get your day one started.

Remember: DeadBugs are a must.