Using boarding / pet sitters:
Ask if raw is an option to give, check freezer etc
Portion out where possible into daily or even each meal - date them and add your dogs full name too - add supplements, eggs, fish as and when needed.
Leave clear instructions including feeding schedule & removing uneaten food & re-presenting it after appropriate storage
If raw I'd simply not an option see our raw alternatives guide (none are long term but will help you to choose ‘as good as it gets’ for this situation
Dog is travelling with you:
Consider freezer options at your location, may be consider a portable freezer
Fill a poly box or cool box with ice packs for the initial journey if taking food with you
Check out the suppliers map in FEATURES for where to buy local to where you stay
Speak to suppliers who do nationwide delivery to see if they can deliver to you
Some campsites allow use of a freezer so it is worth checking this also
If in a caravan, lodge or property, check the freezer & fridge capacity before you go.
Remember water, bowls, collars / harnesses with tags, leads, up to date microchips
If UK Based some pre-made dog safe bone broth like Alexander's Natural or Karnlea
Make a note of vets local to where you stay, just in case required
Take extra care with ticks especially in the countryside