you could enter/finish a game for the contest even with the vacation , it all depends on planning. Maybe save the more in depth writing for vacation or whatever you can do on your tablet and work on mechanics/resources before the trip.
I.e. say ur making a shopkeeper game with a crafting mechanic. Before your trip you do some basic planning, iron out how the crafting/selling system will work and create/find the sprites for the various items/characters you know will be in the game. Then on your trip, you write/plan out the story and quests. Then after your trip, put it all together.
It all depends on your time management/ planning skills. Good Luck!