Depends on how you want to handle it. You can certainly go to amazon and find a new transformer that has a longer cord. Make sure it's 12v and *at least* 200ma.
Barring an extension cord (for the transformer to wall side), you can make an extention cord for the other side. I've done it multiple times. On Amazon, you can pick up barrel connectors with screw terminals Get a pack of them and attach some wire between two connectors (make sure to grab one female and one male). I've typically just used whatever small gauge wire I have laying around. I've used thermostat wire, doorbell wire, garage door opener wire etc. 12v/200ma is very little, you don't need special. I just use those types of wires because it they come in pairs (or 5+ for t-stat wire)
Here's what I've used, plenty of times, in the past:
amazon.com/gp/product/B06Y4YXRMC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
and for wire
amazon.com/gp/product/B00QTCBZ4I/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
or anything along the lines of this amazon.com/Southwire-64267101-White-Bell-Wire/dp/B075TSZRSL/