Actually the two are somewhat contradictory. Trump getting desperate as his reelection time draws near would make him more amenable to give out concessions hoping for a quick deal, not less. So PRC is better off negotiating with him within the next 6 to 12 months.
There is the assumption that the next “sane one” will be conciliatory to PRC. This is only an assumption. There is a strong bipartisan majority in Congress as well as conviction within the Pentagon that Communist China needs to be dealt with. Almost everyone making comments on the trade war topic in here misses this extremely important fact. For instance, there was always the danger that Trump would trade the crown jewel (Taiwan) for a trade deal. The new Taiwan Relation Act amendments passed unanimously by Congress exactly with the intention to foreclose this option.
There is another assumption that PRC can play “the long game” because Xi does not need to be reelected. Whereas this is formally true, CCP faces their own internal pressures.
CCP lacks any democratic legitimacy whatsoever. I am sure this website will stay far clear from posting any news on the massive protest in Hong Kong yesterday, which by some account drew as many as 1.03 million people. To maintain its one-party rule, CCP is utterly dependent on high economic growth to a degree the 2 main parties in USA can never be. Intra-party intrigue and plots, and even just the possibilities thereof, pose limits to what Xi can do more stringent than those of simple democratic reelection.
The reality is USA has hundreds of tools available to squeeze CCP and PRC. The “next sane one” may be much more adept at wielding those than Trump.