If that come to pass, especially if GOP takes both houses, presumably they will be able to do it in the lame duck session, assuming that Manchin and Synema stick with them on it, which one of them might not. But as a budget matter, it can pass by reconciliation, which avoids a filibuster. Can be passed with only 50 votes plus VP Harris in the Senate. There are several specific ways they can do it, with it not really mattering which they do, just that they are able to do it if this comes to pass, which looks highly likely at least with respect to the House of Representatives, if not definite.
We have seen the GOP play games with the debt ceiling in the past, most damagingly in 2011, although sometimes when they have done so, they have suffered negative political feedback. Indeed, fear of that has in the past allowed "more reasonable" Republicans in the House, where these efforts seem to have always emanated from, to eventually cut some sort of not too bad deal with the administration before the plug got pulled and an actual market-damaging default happened.
The problem now, as we pretty much all know, although this matter is not getting much attention, is that that on top of the general polarization, the House GOP members are becoming increasingly radical right, with a whole bunch of seriously crazy types likely to enter the House with this election, even if they do not take control. The moderate GOPs are retiring or getting primaried out for insufficient Trumpiness, and a bunch of election deniers and QAnon followers and so forth will certainly be coming in. And if GOP takes the House, if Kevin McCarthy is even able to get himself elected Speaker rather than someone much further right, he will be under severe pressure from the extreme wing of the party to make seriously wild demands that would be very damaging to put in place, with the Biden admin going to be resisting hard, and with these bomb throwers more likely to be willing to go all the way to pushing an outright default, even possibly with the conscious plan of bringing about an economic crash they can blame on Biden in 2024.
The danger of this is really seriously high, and it needs to be nipped in the bud. I understand that many think that somehow the debt ceiling is some sort of sacrosanct thing, having been around in some form or other for over a century. But it is not. It has never made any sense and no other nation has anything like it, although some have rules limiting the sizes of budget deficits, a different thing. Several of us here, most certainly including me, have posted on this general matter numerous times in the past. And we have long argued that the debt ceiling should simply be abolished. It serves no useful purpose, and only opens our governing process to serious mischief. Heck, even though a default was avoided in 2011, it came close enough that it led to a debt downgrade for the US.
So, Dems, if you lose a house of Congress, eliminate the debt ceiling, please!