Sorry for the slow reply. Works gets in the way!
Here is how I created the maps in google and included them in Blogger. Like anything on a computer there is no doubt dozens of different ways to achieve this. I stumbled across this and it worked so I kept using it.
First of all get your track logs downloaded. I have mine saved as KMZ files though I know there are other GPS formats. For another project I downloaded some free tools to convert between various formats, so it is all doable.
Launch Google Maps and sign in. (You will need a Google account – free).
Select Create a new map, then import
On the next window select ‘select a file from your computer’. Select a KMZ file
Tune up the presentation to your liking (I use the ‘base map’ option and change to satellite), then select ‘share’
Change the access to public, and copy and paste the ‘link to share’
The link can then be included in Blogger post with the 'link' button. Paste the URL in, edit the title text and you are good to go!
There is a lot more that can be done with layers etc but I never found the need to dive deeper.