I have a couple of e-vouchers for cancelled trips that will expire in April and May of 2023. Can I book a trip before the expiration date of a given voucher, for travel that begins after the voucher expiration? And if I do that, and then want to cancel/change the new trip, what happens to the value of the e-voucher used to purchase that trip?

I can't find any info on the voucher or the Amtrak website. Thanks in advance for any help.