Starting "tomorrow" (now yesterday) which means this is too late I guess, unless you are reading it on the road somewhere.

That would be a lot of cash to plunk on Sirius, which I never find to be worth it anymore. The way they divide music is not the way I like to listen, so I use Pandora. But, I am also typically driving where I get signal the entire trip. Out there, you won't have signal all the time. I drove in NV/UT/AZ in 2010 for the first time out of range without the sat radio, and we had to endure some periods of silence instead as we were not well prepared for that. The previous year we had a different trip out that way, but we still had our own sat radio subscription then and brought it with us. These days when out of range we would do an audiobook instead.

Spotify Premium allows downloading tracks for offline use so if you didn't spring for the sat radio you could sign up for Spotify when you have a connection (preferably wifi in a hotel or wherever you're staying) and download some music that you could play when you're out of cell range.