Try to get rooms with kitchenettes.

Prepare meals beforehand, storing in serving size containers.

Bring a cooler! Meat should be frozen. Veggies need only be chilled.

If desired, add ACV to preserve meat - a bit more than 1tbsp per lb of meat.

Freeze small bottles of water to act as cold packs. They don't melt into a mess!
As bottles thaw, they provide drinking water for you and the dog.

Pack a cooler picnic style with foods appropriate for you and the dog.

Share meat sandwiches or subs, quiche, cheeses, fruits, bread, anything healthy.

Purchase or bring canned fish - don't forget the can opener!

Buy fresh produce locally if supplies run low. Pack enough supplements to last.

In restaurants, set aside healthy foods and get a "doggy bag."

Don't worry about perfect balance - the dog is on vacation too!