There is NO way on God's green earth I would ever feed an 8ft + boa in full feeding mode outside of its enclosure and then try to move it back again. I am a little strange, but not crazy.
1. Chances are, your boa won't refuse. They are not like BPs and tend to be garbage disposals.
2. If he IS picky, just leave the prey in there (I'm assuming you feed pre-killed or f/t??) and he will most likely feed sometime during the night.
3. Lower your temps a wee bit. Boas do seem to like it a touch cooler. 78 and 88 work well.