Guys/gals - I've got a dilemma I'm hoping you can help me with. We're considering getting a dog for the family. Likely a "medium-to-full size" dog that can stay outside a lot, jump in the creek, etc but will still be inside when it's cold, etc. Not a small, trip over it, never goes outside kind of dog. I like blue healers, labs, german shorthairs, etc. We're looking at rescue's primarily.
The dilemma is that when I was growing up out in the country and we had a dog, we were home a lot. We were away maybe a couple weekends a year (weddings, graduations, etc) so leaving the dog with the neighbor or just to run free in the country wasn't much of an issue. It drank from the creek, found something dead to eat or the neighbor would throw it some food on Saturday, etc. Relatively low maintenance. Our family (mom, dad, 2 boys ages 16 & 4) lives in the city, travels a lot, around 35-40 weekends a year with the occasional 3-4 day weekend in there along with holiday weekends. Typically a 4 hour drive each way, sometimes 6 hours depending on where we're going, who we're visiting. Even during the week we're both working or taking kids to activities out of the house 10+ hours a day so we're not home much even when we're home

. We most often travel to visit friends/family so once we're there on the holidays/weekends we've got a pet friendly place to stay.
We had a cat who didn't travel too much and was OK alone for the weekend. We had a bird for a couple years which wasn't too bad. It also typically stayed at home while we traveled (before the 4 year old came along).
Any suggestions on how to best travel this much with a dog (or to even get a dog at all)? I like dogs, but don't want to get in a situation where its more of a burden than an enjoyment (for both the family and the dog).
If we traveled less and/or were home more it wouldn't be much of an issue - I'd love to have a shop dog (right now I have neither!).
Any thoughts, opinions, suggestions are welcomed!