Pep guadiola will be very happy to give Manchester City the champions League before he leave England,is the only trophy he has not won for Manchester City,infact since he left Barcelona he has never won the champions League,all through his time at Bayern Munich (Germany)he did not win it. so I think he will be obsessed with it and would love to win it at City,with the type of squad he has he should be confident,but that does not mean he is going to surrender the premier League to Liverpool, we all know that he is a winner and would love to win everything.
Pep Guardiola was success with all domestic league from La Liga, Bundesliga until primer league but he failed with giving champion league trophy for Bayern Munich and Manchester City. I think he not has any reason leaving Manchester City as soon possible because still get trusted from Manchester City owner although never give champion league trophy but as top team on primer league. Several years with Manchester City, Pep Guardiola was success give several primer league trophy for Manchester City and I think he will extended several years later on Ettihad Stadium.
But there are some rumors about this and the rumor that is growing is that he doesn't want to extend his contract which will expire in 2023 even though some time ago he was already looking for a strong candidate to replace him and the one he recommended was Graham Potter.
I think even though he never won the UCL title here but as you said he was quite good at City and actually if you look at it until now it seems that City officials are quite satisfied with that