Enterprise Value and Debt question

On the job so apologies if worded a little lengthy. 

You got 2 questions wrapped into 1. The first one is how to think about EV when EBITDA dips. Generally it makes little sense to analyze EV and by connection EBITDA on an isolated, 1 year basis, but more in a dynamic context (as you allude to already). In other words, look into next year's EBITDA and see how much visibility you have towards actually achieving pre-COVID levels and from that try to understand what the new normalized EBITDA looks like. That's your basis for your EV calculation.

On your second question, which is whether you should invest in the notes, the debate is much more nuanced since it involves an analysis of the liquidity of the company, FCF generation, covenants, price (trading below par doesn't mean much - how much below par and how do returns look like when you account for the risks embedded in that EBITDA?). But just from a credit support perspective (which is an oversimplification, can't disclaim that enough), stress test your next-year EBITDA and your normalized levels, run a recovery analysis on those scenarios and see where you land. If relative to the price you get an asymmetric enough risk-return distribution, then the notes could make sense as an investment.