If I was using flights I'd probably use an "all in one" so flight delays, baggage, etc is all covered. However, we are driving so I've reasoned that I don't need everything in an all in one so I am placing to have two products.
First, I'm looking at medical insurance coverage when out of the country through GeoBlue. My understanding is that it's secondary insurance but that they'd pay a bill and submit a claim to my primary (which would then be denied and GeoBlue would assume responsibility, but this can be a headache for secondary insurance putting more on the patient, and this is one reason primary medical travel insurance is a good idea if all else is equal). My understanding is that this would cover emergency transport like medivac helicopter
Second, I've looked at a cheap no frills insurance to cover travel interruption and travel cancelation due to stuff like, an illness or death in family (elderly parents), lost job, hurricane, etc.
I don't need loss and delay insurance so for me unbundling and separate plans looks cheaper for the coverage I actually want.
Best tip is to figure out what you want covered. Do you need preexisting existing coverage? Pre-existing condition coverage usually begins when making the first trip payment so not necessarily paid in full date so you may or may not be eligible for the pre-existing condition (usually plans say uncovered unless meeting waiver requirements, rather than affirming coverage). Want primary medical or play with secondary? How much medical coverage do you want? (We looked for minimum $100k but some want more or are okay with less). How much medical evacuation insurance do you want? Want "cancel for any reason"? If there a delay how much daily insurance do you want vs. could you stomach and pay yourself?
So after you've thought about what you want, use
squaremouth.com and/or
insuremytrip.com to compare. Use the filters on the websites and it'll spit out stuff that meets your requirements.
The Costco option will not be in there but you can compare coverages pretty easily.
ETA: mods, apparently one of the websites is blocked out. Sorry about that.