I have an old backbone-rails application which was written back in 2011 (probably dependencies last updated in 2013 or so). It has a very old UI so I thought to update it by applying nice bootstrap material design. It is not so simple as it sounds because jquery is a backbone dependency which is 2011 version. As I import any bootstrap theme, things like navigation drawer don't work because backbone's jquery (older version) overrides newer jquery due to order of imports. If I remove older jquery and just use newer one from CDN, app crashes due to probably some methods which were there in older jquery but not in newer one. Even if I try to upgrade backbone version to latest, app breaks (as expected).
I am confused, how to start about upgrading this ? I understand that this is a very specific problem, probably some experienced guy can help who had a similar one.
PS : No option to move to angular or react, backbone code is too much to be rewritten right now (and is a management call)