If there is no roof vent, then get that free-standing FanTastic. Open all the windows and put it in front of your biggest window, or wherever you think it's better. Don't worry about cable length, take a piece of a lamp cord and make the cable few feet longer if you have to - max draw 3A is a low current.
A good point on 100W (?) solar. If left On for 12 hours, at 3A this fan will draw 1/3 of the "usable" charge of a pair of 6V GC. Not a disaster for a weekend warrior though.
I put a question mark there, because have come to think like "solar homes crowd" - with solar you go big or go home. Small 100W solar is easy to use as a portable, but this has its drawbacks, and 100W won't let you camp without a generator anyway. OTH, when taking pains of installing a permanent solar, it makes sense to max it up. With 300-500W solar in AZ it's possible to live off solar without a generator until you have to run the A/C. Definitely possible in winter.