Welcome to the forum.
Heat for a dashcam is only a issue if you are going to use parking guard and live in a hot / sunny place, otherwise for just sitting there waiting for you to do your next drive they are fine.
Many / most cameras today have wifi, but only in the dumb sense to do setting changes and if pushed into a corner DL a file over the not fast wifi, you need to turn it on first however, otherwise best kept off.
There also is viofo cameras with 1440p on the front camera, the all new A139 also come in a 2 channel version if that shape suit you better, also the A139 have not screen, though those generally go out after a few seconds so no nuisance when driving at night.
Make sure to not forget your new camera once installed, you be wise to look over the card content every few months, it only take 10 - 15 minutes or so on the computer with the card in a card reader.
Dont have to watch it all, focus on first / last clips in drive sessions, and them starting / ending in reasonable places and not just some random place on a road. so just viewing X seconds of the files you inspect will be fine.
And another advise would be to get your memory card local, and get one that have warranty when used in dashcams ( many dont have that )