Does your current truck have a hitch in it? What is the GVW of the trailer? How overloaded will you be? While I don't advocate using the wrong truck for a one time trip I would consider it.
On the other hand what are your plans for the 5'er in the long run.
Do you have plans to upgrade your current truck to accommodate the new 5'er?
Finding a rental truck with a 5th wheel hitch may be a challenge.
19'Duramax w/hips, 2022 Alliance Paradigm 390MP >BD3,r,22" Blackstone
r,RV760 w/BC20,Glow Steps, Enduraplas25,Pedego
BakFlip,RVLock,Prog.50A surge ,Hughes autoformer
Porta Bote 8.0 Nissan, Sailun S637