To create a new Lightroom Classic catalog to work on a laptop abroad How to deal with syncing

I will be living abroad for two month. I was thinking of creating a new catalog for lightrooom classic  in my travel laptop  to work on the pictures that I will take abroad and then when I come back, merge the new  smaller catalog ,  with my current catalog. The question is what happens with the syncing of  catalogs when having multiple lightroom cc catalogs in the same computer (laptop)? . Currently I can see my catalog  that is housed in my desktop accross my  laptop and my phone. Should I dissable syncing in the NEW catalog and use it only to edit the new photos? If I do that , will I still have access to my current catalog in my laptop because that is the one that is synced?  Another way around would be to upload the new pictures to lightroom cc  from abroad and when I come back  to move them into lighroom classic  by changing the location of the files BUT I rather edit with lightroom classic whic  is  the main reason why I would create a new catalog.  I know that I can copy my current catalog with all my photos to a portable hard drive and then work with it from my laptop but I am afraid of corrupting the catalog working that way. I had a bad experience in the past.

Thanks!