Excellent advice George. Many travelers break the journey into two or even three segments. You can leave your bike in certain countries, fly home and then fly back at some point and continue.
In three months you could get a pretty good feel for Mexico and maybe part of Cent. America, depending on side trips and interests. So much of Mexico gets missed. Worth seeing for sure, and you need a couple months to see it properly.
Do what you can, make the trip.
Going fast is an utter waste of your time.
Been there, done it. No point. I'd rather just ride to San Miguel de Allende, or some other idyllic locale and spend three months just hanging out, doing day loop explorations, then ride home when time is up. Up to you.