upgrading only Emacs in LTS

[Sivaram Neelakantan <nsivaram.net@gmail.com>]

I'd like to upgrade Emacs to the 26.x series and only that and it's
dependencies.  Is there a way to do that?  A search on the web showed
some confusing instructions.  Below are, hopefully, enough information
for any suggestions. 


--8<---------------cut here---------------start------------->8---
user1@DESKTOP:~$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=18.04
DISTRIB_CODENAME=bionic
DISTRIB_DESCRIPTION="Ubuntu 18.04.3 LTS"
user1@DESKTOP:~$ emacs --version
GNU Emacs 25.2.2
user1@DESKTOP-D9U3P3E:~$ sudo apt-cache policy emacs-nox
emacs-nox:
  Installed: 47.0
  Candidate: 47.0
  Version table:
 *** 47.0 500
        500 http://archive.ubuntu.com/ubuntu bionic/universe amd64 Packages
        100 /var/lib/dpkg/status
user1@DESKTOP:~$ sudo apt-get install --only-upgrade emacs-nox
Reading package lists... Done
Building dependency tree
Reading state information... Done
emacs-nox is already the newest version (47.0).
--8<---------------cut here---------------end--------------->8---


sivaram
--