2 TN visas at once?

I'm going to be moving from LA to San Fran at the end of October. I will be leaving one job and then starting the new job mid-November. I currently have a TN for the first job till Nov 1. We are planning a trip back to Canada and I want to get my TN for the second job at that time, but still need a TN for the first job cuz I won't be quitting that one till Oct 20.

Can I hold 2 TN visas at once? I have my letter of employment from both jobs to renew, but does it matter that the first employer says I will be employed with them for the next 3 years when in reality I will only be with them for a Couple more weeks? Should I get HR from the first job fix my letter to reflect my quit date? Or not bother if you can hold 2 TNs at once?

Thanks!

You certainly can hold 2 (or more TNs) at one time.
Simple keep the old Job 1 I-94 (you must insist that you are keeping it) when applying for the Job 2 TN.

I might reconsider even presenting the renewal of your Job 1 TN (since you are going to leave before the current one expires anyways), unless the Job 2 petition is denied for some reason (they mey feel it is too early to give you the new TN) then renew #1, and go back once you have #2 fixed (or it is closer to the start date).

You MUST keep the first TN (the I-94) until (a) you actually get the second TN, AND (b) you are no longer working for #1.