The difference between “112 bits” and “128 bits” matters for compliance to certain standards, but not for security. Both are out of reach of current computing technology. Furthermore, 112 bits for RSA-2048 is an estimate based on current attack techniques. A disruption such as quantum computers that are useful at cryptanalysis would break both RSA and AES, but in different ways — RSA would be trivialised at any pratcical key size, while symmetric cryptography would only have its “bit strength” halved.
So either you have to comply to some strict standard, and then you need to do what the standard says; or you don't have to comply to some strict standard, and then RSA-2048 is fine for authentication (which is what it's used for here). This is true even if you're exchanging long-term secrets: to break the security of your VPN by attacking the RSA part, the attacker has to breach it live, to cause the client to accept a fake server. The use of ECDHE provides forward secrecy, so there's no way to reconstruct the plaintext from the ciphertext and the server's RSA key later (if the attacker managed to break RSA, or more realistically to obtain the key). If you are concerned about very long-term secrecy, switching to AES-256 is actually more useful than moving away from RSA-2048 (and then you should also check that you're using a stronger curve, at least P384R1).
However there's little reason to use RSA these days. Elliptic curve cryptography has generally better performance for the same security. Your default choice should be
AES_256 instead of
SHA384 instead of
CCM instead of
GCM), sticking to widely-supported ciphersuites. EdDSA and ChaCha20_Poly1305 are also good choices if supported. RSA as used in
TLS_(EC)DHE_RSA_xxx ciphersuites has better performance than elliptic curve methods on the client side (at the cost of worse server-side performance) if you're only authenticating the server, which is often the case on the web. But if the two sides authenticate each other, as is normally the case on a VPN, elliptic curves have better performance.