If interrupting a laser hair removal treatment in the meantime before continuing, is it okay to use depilatory cream?

The reason you were instructed to only shave was because the laser needs access to the hair so that light travels down it and delivers its energy to the follicle. When shaving, hair is still accessible at the surface. Other methods remove it below the surface. 
If you have no plans to resume treatment in the near future, you can resume any desired method you prefer.
When you do resume LHR, shave for 4 - 6 weeks prior and purchase a full series. This is due to the cycles your hair grows. Lasers can only kill follicles when the are active. Plan your future treatments to match the average hair cycle activation of every 6 weeks. A treatment every 5 - 7 weeks is OK, but get out of that cycle, you may as well start a full series all over again.
Nearly all countries now have LHR. I recommend trying to pick the treatments up again where ever you go. In lesser developed countries, stick with the most reputable providers or risk possible serious adverse events.
Bon Voyage!
Arbella Sarkis MD        

If you are no longer doing laser hair removal the rules of it no longer apply.  You can do anything that you were doing to hair removal prior including waxing, plucking, threading and depilatory creams.  You will no lose what you have done.  If at some point you wish to resume laser hair removal discontinue those methods and start just shaving again for about 4-6 weeks to allow the hair to grow back in.  Follicles with actively growing hair need to be present for laser hair removal to work.