For me it is not guaranteed, and even Chelsea, Man City and Newcastle are still be able of shifting Nottingham position. Chelsea only has a 3 point difference with Nottingham and only needs 1 win for Chelsea to shift Nottingham position.
I don't believe you if you say that only Nottingham are playing consistently while Nottingham have lost their last 2 games. The defeat is proof that there is no guarantee that Nottingham can stay consistent and still get a UCL ticket. There are 6 games left that can change something good to be very bad.
Chelsea are going to find it difficult except they put out extra ordinary performance in this few games left. Half of the matches remaining will be played against tough clubs like Liverpool, Newcastle and Nottingham Forest, I never included Fulham as we know how sometimes they refuse to get beaten by big teams.
When it gets to limited games left for the season even the season underdogs begins to play better. Nottingham Forest lost 2 games in a row and still directly under Arsenal, all teams are trying their best but I only can speak of a team I see that has done so well beyond expectations.
Chelsea really couldn't take advantage of the opportunity against Ipswich Town, Chelsea had to share the points. Even if they win this match, it will give Chelsea a little hope to play in the Champions League next season. But now with the remaining matches left, especially as you said the opponents they face are many strong teams, their chances of playing in the Champions League are getting harder. Chelsea is not completely stable, the next match will be against Fulham if this also fails to get three points then it will be more difficult for Chelsea.
If we talk about the Champions League, I actually see Man United's chances are bigger than Chelsea's. If Man United wins the Europa League, Man United will play in the Champions League, but if Chelsea fails to enter the top 5, they will not qualify for the UCL even if they win in the conference league.