The month marked significant changes with new owners, The Friedkin Group, and David Moyes replacing Sean Dyche as manager.
Moyes' return sparked an upturn in form, with Everton winning three consecutive Premier League matches before their FA Cup loss to Bournemouth.
On transfers, Thelwell stated: “I think everybody recognises it is a very difficult window. You need two things to happen - you need somebody who wants to buy and somebody who wants to sell and that doesn’t happen so much now, particularly in this winter window.
“So we always knew it was going to be tough and we always knew it was going to be difficult to bring in new bodies.
“We were really pleased to get Charly (Alcaraz) in, a player we watched for some time, an Argentinian international, we liked him before when he went to Southampton and we tracked him when he went to Flamengo and it was good to get him in the building and I think he will provide us with a lot of intensity and energy and he is also a very good footballer.”