After reading all of the positive comments about using the SL Mini, Bosker insisted we up our game. We now have one, with a waterproof case, the Anker Prime Power Bank, an extra 50' power cord for the mini for when the Bison chomps the old one, and a USBC to DC5521 adapter cord.
Bosker and I are ready to rock-n-roll, with continual connectivity this summer, on our trip from Texas to Yellowknife, NWT, Canada!! (according to SL, Yellowknife has connectivity all way up there at 62.4N)
Thanks, everyone, for blazing this trail and informing the Ollie family about this great accessory.